Add files using upload-large-folder tool

marked/Y/T-REC-F.747.8-201511-I_PDF-E/raw.md

@@ -0,0 +1,620 @@
+
+
+# ITU-T
+
+# Y.4412/F.747.8
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+(11/2015)
+
+SERIES Y: GLOBAL INFORMATION  
+INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS  
+AND NEXT-GENERATION NETWORKS, INTERNET OF  
+THINGS AND SMART CITIES
+
+Internet of things and smart cities and communities –  
+Frameworks, architectures and protocols
+
+SERIES F: NON-TELEPHONE TELECOMMUNICATION  
+SERVICES
+
+# --- **Requirements and reference architecture for audience-selectable media service framework in the IoT environment**
+
+Recommendation ITU-T Y.4412/F.747.8
+
+## ITU-T Y-SERIES RECOMMENDATIONS
+
+## GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS, INTERNET OF THINGS AND SMART CITIES
+
+## GLOBAL INFORMATION INFRASTRUCTURE
+
+|                                           |             |
+|-------------------------------------------|-------------|
+| General                                   | Y.100–Y.199 |
+| Services, applications and middleware     | Y.200–Y.299 |
+| Network aspects                           | Y.300–Y.399 |
+| Interfaces and protocols                  | Y.400–Y.499 |
+| Numbering, addressing and naming          | Y.500–Y.599 |
+| Operation, administration and maintenance | Y.600–Y.699 |
+| Security                                  | Y.700–Y.799 |
+| Performances                              | Y.800–Y.899 |
+
+## INTERNET PROTOCOL ASPECTS
+
+|                                                                    |               |
+|--------------------------------------------------------------------|---------------|
+| General                                                            | Y.1000–Y.1099 |
+| Services and applications                                          | Y.1100–Y.1199 |
+| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 |
+| Transport                                                          | Y.1300–Y.1399 |
+| Interworking                                                       | Y.1400–Y.1499 |
+| Quality of service and network performance                         | Y.1500–Y.1599 |
+| Signalling                                                         | Y.1600–Y.1699 |
+| Operation, administration and maintenance                          | Y.1700–Y.1799 |
+| Charging                                                           | Y.1800–Y.1899 |
+| IPTV over NGN                                                      | Y.1900–Y.1999 |
+
+## NEXT GENERATION NETWORKS
+
+|                                                                   |               |
+|-------------------------------------------------------------------|---------------|
+| Frameworks and functional architecture models                     | Y.2000–Y.2099 |
+| Quality of Service and performance                                | Y.2100–Y.2199 |
+| Service aspects: Service capabilities and service architecture    | Y.2200–Y.2249 |
+| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 |
+| Enhancements to NGN                                               | Y.2300–Y.2399 |
+| Network management                                                | Y.2400–Y.2499 |
+| Network control architectures and protocols                       | Y.2500–Y.2599 |
+| Packet-based Networks                                             | Y.2600–Y.2699 |
+| Security                                                          | Y.2700–Y.2799 |
+| Generalized mobility                                              | Y.2800–Y.2899 |
+| Carrier grade open environment                                    | Y.2900–Y.2999 |
+
+## FUTURE NETWORKS
+
+|                 |               |
+|-----------------|---------------|
+| CLOUD COMPUTING | Y.3000–Y.3499 |
+|                 | Y.3500–Y.3999 |
+
+## INTERNET OF THINGS AND SMART CITIES AND COMMUNITIES
+
+|                                                         |                      |
+|---------------------------------------------------------|----------------------|
+| General                                                 | Y.4000–Y.4049        |
+| Definitions and terminologies                           | Y.4050–Y.4099        |
+| Requirements and use cases                              | Y.4100–Y.4249        |
+| Infrastructure, connectivity and networks               | Y.4250–Y.4399        |
+| <b>Frameworks, architectures and protocols</b>          | <b>Y.4400–Y.4549</b> |
+| Services, applications, computation and data processing | Y.4550–Y.4699        |
+| Management, control and performance                     | Y.4700–Y.4799        |
+| Identification and security                             | Y.4800–Y.4899        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+## Recommendation ITU-T Y.4412/F.747.8
+
+# Requirements and reference architecture for audience-selectable media service framework in the IoT environment
+
+## Summary
+
+Recommendation ITU-T Y.4412/F.747.8 describes requirements and reference architecture for the audience-selectable media (ASM) service framework. The ASM service provides audiences with media selection options according to their interests and preferences. Examples of media selection options include the selection of an object of interest, and the selection of an interested camera object among multi-camera objects providing different views.
+
+## History
+
+| Edition | Recommendation       | Approval   | Study Group | Unique ID*                                                                |
+|---------|----------------------|------------|-------------|---------------------------------------------------------------------------|
+| 1.0     | ITU-T Y.4412/F.747.8 | 2015-11-29 | 16          | <a href="http://handle.itu.int/11.1002/1000/12620">11.1002/1000/12620</a> |
+
+## Keywords
+
+ASM, audience-selectable, Internet of things, media.
+
+---
+
+\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/1830-en>.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2016
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## Table of Contents
+
+|   |                                                                              | Page |
+|---|------------------------------------------------------------------------------|------|
+| 1 | Scope.....                                                                   | 1    |
+| 2 | References.....                                                              | 1    |
+| 3 | Definitions .....                                                            | 1    |
+|   | 3.1 Terms defined elsewhere.....                                             | 1    |
+|   | 3.2 Terms defined in this Recommendation.....                                | 2    |
+| 4 | Abbreviations and acronyms .....                                             | 2    |
+| 5 | Conventions .....                                                            | 2    |
+| 6 | Overview of audience-selectable media (ASM) service .....                    | 2    |
+| 7 | Requirements of ASM service framework .....                                  | 4    |
+|   | 7.1 Service requirements .....                                               | 4    |
+|   | 7.2 Functional requirements .....                                            | 4    |
+| 8 | Reference architecture of ASM service framework .....                        | 5    |
+|   | 8.1 Reference architecture .....                                             | 5    |
+|   | 8.2 Camera objects function .....                                            | 7    |
+|   | 8.3 Camera control server function .....                                     | 8    |
+|   | 8.4 Video playback terminal function .....                                   | 9    |
+|   | Appendix I – Use cases for ASM service .....                                 | 10   |
+|   | I.1 Use case for an ASM broadcasting service using multi-camera objects..... | 10   |
+|   | I.2 Use case for an open screen service using multi-camera objects .....     | 11   |
+|   | Bibliography.....                                                            | 13   |
+
+## **Introduction**
+
+Recently, demands for personalized media and interactivity in the media service are increasing and media service platforms are needed to support the fast development and deployment of new multimedia services/applications by reconfiguration of the existing service components. Due to the expansion of the Internet of things (IoT), objects related to media services can be identified and recognized by people or other objects. Also, the IoT enables person-to-object and object-to-object communications as well as person-to-person communication.
+
+Audience-selectable media (ASM) service enables viewers to be interactive and select preferred media in the running time by providing media selection options.
+
+## Recommendation ITU-T Y.4412/F.747.8
+
+# Requirements and reference architecture for audience-selectable media service framework in the IoT environment
+
+## 1 Scope
+
+This Recommendation defines requirements and reference architecture for audience-selectable media (ASM) service in the Internet of things (IoT). The scope of this Recommendation includes:
+
+- concept of ASM service framework;
+- requirements of ASM service framework;
+- reference architecture of ASM service framework; and
+- functional entities of ASM service framework.
+
+## 2 References
+
+None.
+
+## 3 Definitions
+
+### 3.1 Terms defined elsewhere
+
+This Recommendation uses the following terms defined elsewhere:
+
+**3.1.1 device** [b-ITU-T Y.4400]: An apparatus through which a user can perceive and interact with the web.
+
+**3.1.2 Internet of things** [b-ITU-T Y.4000]: A global infrastructure for the information society, enabling advanced services by interconnecting (physical and virtual) things based on existing and evolving interoperable information and communication technologies.
+
+NOTE 1 – Through the exploitation of identification, data capture, processing and communication capabilities, the IoT makes full use of things to offer services to all kinds of applications, whilst ensuring that security and privacy requirements are fulfilled.
+
+NOTE 2 – From a broader perspective, the IoT can be perceived as a vision with technological and societal implications.
+
+**3.1.3 object** [b-ITU-T Y.2002]: An intrinsic representation of an entity that is described at an appropriate level of abstraction in terms of its attributes and functions.
+
+**3.1.4 resources** [b-ITU-T Y.4400]: The term "resource" is whatever might be identified by a URI.
+
+NOTE – Familiar examples include an electronic document, an image, a source of information with a consistent purpose (e.g., "today's weather report for Los Angeles"), a service (e.g., an HTTP-to-SMS gateway), and a collection of other resources. A resource is not necessarily accessible via the Internet; e.g., human beings, corporations, and bound books in a library can also be resources. Likewise, abstract concepts can be resources, such as the operators and operands of a mathematical equation, the types of a relationship (e.g., "parent" or "employee"), or numeric values (e.g., zero, one, and infinity).
+
+**3.1.5 thing** [b-ITU-T Y.4000]: With regard to the Internet of things, this is an object of the physical world (physical things) or the information world (virtual things), which is capable of being identified and integrated into communication networks.
+
+### 3.2 Terms defined in this Recommendation
+
+This Recommendation defines the following terms:
+
+**3.2.1 camera control server:** A server that selects and updates camera objects, camera object groups, and the main camera object. It also controls camera objects.
+
+**3.2.2 camera object:** A device that captures and tracks objects of interest. It can also transmit and receive the tracked position of each object of interest to both other camera devices and a camera control server through the Internet. Its pan-tilt-zoom may be controlled by the camera control server for tracking objects of interest.
+
+**3.2.3 camera object group:** A group of camera objects that capture the same object of interest whose occupied region size in the frame is greater than the pre-defined value.
+
+**3.2.4 main camera object:** A camera object that captures a main broadcasting video. The initial main camera object is selected by audiences or the broadcaster. The main camera object can be changed to the sub-camera object during the service.
+
+**3.2.5 object of interest:** A moving person or a moving thing in the video of which the service audience may have interest.
+
+**3.2.6 sub-camera object:** A camera object that is not selected as a main camera object. An initial sub-camera object is usually selected by the broadcaster. The sub-camera object can be changed to the main camera object by audiences during the service.
+
+## 4 Abbreviations and acronyms
+
+This Recommendation uses the following abbreviations and acronyms:
+
+|       |                             |
+|-------|-----------------------------|
+| ASM   | Audience-Selectable Media   |
+| FE    | Functional Entity           |
+| ID    | Identifier                  |
+| IoT   | Internet of Things          |
+| URI   | Uniform Resource Identifier |
+| Wi-Fi | Wireless Fidelity           |
+
+## 5 Conventions
+
+None.
+
+## 6 Overview of audience-selectable media (ASM) service
+
+Internet of things (IoT) and web of things (WoT) enable physical devices to be accessed as resources and services/applications of the web.
+
+As new multimedia services/applications are emerging, media service platforms need to support fast development and deployment of new multimedia services/applications by reconfiguration of the existing service components. Also, media service devices, such as cameras, are beginning to provide wireless fidelity (Wi-Fi) technology.
+
+IoT-applied media service enables objects in media service to be identified and recognized by people or other objects; IoT also enables person-to-object and object-to-object communications as well as person-to-person. This realizes the smart media service where objects can be automatically reconfigured to create and deliver media content according to the audience's demands and preferences.
+
+In the current broadcasting service, a suitable camera object is selected among available camera objects, video from the selected camera object is encoded, and the encoded video is broadcasted to viewers. Attributes of the content and service region are considered for broadcasting.
+
+This traditional broadcasting service does not provide any options to audiences to select various views from different camera objects in the same scene. The lack of this option causes audiences to remain passive.
+
+The ASM service enables audiences to be interactive and select preferred media in the running time by providing media selection options. Examples of media selection options include the selection of an object of interest and a selection of an interested camera object among multi-camera objects providing different views. Figure 1 illustrates the concept of the ASM service.
+
+As described in Figure 1, there are three components in the ASM service: Broadcaster, audience, and camera management server. These components generate and update object of interest, camera group for each object of interest, and a camera view-video that the audience is interested in, including the following:
+
+- (1) **broadcaster**: The broadcaster shows object of interest candidates to the audience.
+- (2) **audience**: The audience selects one object from the object of interest candidates, selects one of the camera objects in the camera group for the selected object of interest, and watches the selected camera view-video.
+- (3) **camera management server**: The camera management server updates the cameras in each camera group for each object of interest, gets the selection option inputs from the audience, and broadcasts the selected camera-view video to the audience.
+
+![Figure 1: Concept of ASM service diagram. The diagram shows the interaction between a Camera management server, a Broadcaster, and an Audience. The Camera management server manages camera groups for different players. The Broadcaster shows object of interest candidates to the Audience. The Audience selects a camera group, which is then updated by the Camera management server.](367926125450c2bc3f4bdca9d59a62ba_img.jpg)
+
+The diagram illustrates the ASM service architecture and its flow. At the top is the **Camera management server**. It manages two main camera groups: **Camera group A for player 1** (containing Camera 1 and Camera 2) and **Camera group B for player 2** (containing Camera 4 and Camera 5). An **Update** arrow points from Camera group B to an updated version of Camera group B (containing Camera 4, Camera 5, and Camera 6). Below the server is the **Broadcaster**, which receives input from the server and provides **Object of interest candidates** (Player 1 and Player 2) to the **Audience**. The Audience selects a camera group (Camera 4 and Camera 5) for player 2. This selection is then **Updated** to a new camera group (Camera 4 and Camera 6) for player 2, which is then broadcasted back to the Audience. The diagram is labeled Y.4412-F.747.8(15)\_F01.
+
+Figure 1: Concept of ASM service diagram. The diagram shows the interaction between a Camera management server, a Broadcaster, and an Audience. The Camera management server manages camera groups for different players. The Broadcaster shows object of interest candidates to the Audience. The Audience selects a camera group, which is then updated by the Camera management server.
+
+**Figure 1 – Concept of ASM service**
+
+The concept of the ASM service described in Figure 1 can be explained as follows:
+
+- broadcasters first specify the object of interest candidates in the scene (e.g., player 1 and player 2) and then show them to the audience for selection;
+
+- the camera management server constitutes an initial corresponding camera group for each object of interest candidate using all available cameras based on the positions of each object of interest, and each camera;
+- an audience first selects one object from the object of interest candidates (e.g., player 2), and also selects one of the cameras in the selected camera group (e.g., camera 5 in camera group B);
+- the camera management server receives the audience's selections for the camera and object of interest, and broadcasts a selected camera-view video (e.g., camera 5 in camera group B);
+- as an object of interest (e.g., player 2) moves in the scene during the running time, the camera management server updates each member of each camera group based on the updated position of each object of interest (e.g., In Figure 1, camera 5 in the initial camera group B is deleted from the updated camera group B);
+- with updated camera members of each group, the camera management server shows each updated selectable camera list for each object of interest;
+- then, an audience may change which camera view to watch (e.g., from camera 5 in initial camera group B to camera 6 in updated camera group B).
+
+## **7 Requirements of ASM service framework**
+
+### **7.1 Service requirements**
+
+#### **7.1.1 Media selection option**
+
+The ASM service is required to provide audiences with:
+
+- media selection option to select media according to their interests and preferences;
+- video selection option to select one camera object among multi-camera objects;
+- switching option to change the current camera object to another camera object among multi-camera objects.
+
+#### **7.1.2 Object of interest selection option**
+
+The ASM service is required to:
+
+- provide audiences with a selection option of object of interest to select an object they wish to watch;
+- support audiences with changing option of object of interest to in the running time;
+- support identification of each object of interest with an appropriate identifier (ID).
+
+#### **7.1.3 Main camera object selection option**
+
+- the ASM service is required to provide audiences with a main camera object selection option among multi-camera objects.
+
+#### **7.1.4 Camera object group selection option**
+
+- the ASM service is required to provide audiences with the choice of a camera object group selection that captures each object of interest among multi-camera object groups according to their preferences.
+
+### **7.2 Functional requirements**
+
+#### **7.2.1 Functional requirements of a camera object**
+
+Each camera object is required to:
+
+- be able to obtain the position or the tracking result of an audience-selected object of interest in each captured frame;
+- receive the positions or the tracking results of an audience-selected object of interest in each frame of the main camera object as a sub-camera object;
+- convert the tracked position of an audience-selected object of interest in the main camera object to the position of each camera object;
+- receive audience's video selection information from the video playback terminal through the camera control server;
+- share an ID of each tracked object of interest with other camera objects within the same camera object group.
+
+Each camera object selected as a main camera object is required to:
+
+- transmit the positions or the tracking result of an audience-selected object of interest in each frame to the other sub-camera objects and the camera control server.
+
+#### **7.2.2 Functional requirements of camera control server**
+
+A camera control server is required to:
+
+- select camera objects that should be shown to the audience for selection;
+- update members of each camera object group based on the tracking results of the audience-selected object of interest within the appropriate time interval;
+- update the main camera object candidates in each camera object group based on the tracking results of the audience-selected object of interest within the appropriate time interval;
+- recommend the main camera object candidates in each camera object group to the audiences based on the tracking results of the object of interest;
+- notify audiences of updates of members in each camera object group;
+- receive audience's selection information such as an object of interest selection, camera object group selection, and main camera object selection;
+- notify audience's selection information to each audience-selected camera object for video transmission to the audience's video playback terminal;
+- receive the positions or the tracking results of the audience-selected object of interest in each frame of all camera objects within the appropriate time interval;
+- manage each camera object member within each camera object group according to the movement of each object of interest.
+
+A camera control server is recommended to:
+
+- control the pan-tilt-zoom of each sub-camera object according to the tracked position and the size of the object of interest in the frame of the main camera object.
+
+## **8 Reference architecture of ASM service framework**
+
+### **8.1 Reference architecture**
+
+Figure 2 shows a reference architecture of the ASM service framework which consists of ASM service framework functions, functional entities (FEs) of each ASM service framework function, reference points between each ASM service framework function.
+
+![Figure 2: Reference architecture of ASM service framework. The diagram shows three main functional blocks: Camera objects function, Camera control server function, and Video playback terminal function. The Camera objects function contains three FEs: Object of interest processing FE, Camera-to-camera communication FE, and Video transmission FE. The Camera control server function contains three FEs: Main camera object management FE, Camera object group management FE, and Camera pan-tilt-zoom control FE. The Video playback terminal function contains two FEs: Audience's selection options management FE and Video play FE. An Audience is shown interacting with a computer. Information flows are indicated by arrows: I_CO-CS (bidirectional) between Camera objects and Camera control server; I_CO-VP (bidirectional) between Camera objects and Video playback terminal; I_VP-CS (bidirectional) between Video playback terminal and Camera control server; and I_VP-AU (bidirectional) between Video playback terminal and Audience. A reference point Y.4412-F.747.8(15)_F02 is noted near the Audience.](d4af765160d04ecef538e5066006dc77_img.jpg)
+
+Figure 2: Reference architecture of ASM service framework. The diagram shows three main functional blocks: Camera objects function, Camera control server function, and Video playback terminal function. The Camera objects function contains three FEs: Object of interest processing FE, Camera-to-camera communication FE, and Video transmission FE. The Camera control server function contains three FEs: Main camera object management FE, Camera object group management FE, and Camera pan-tilt-zoom control FE. The Video playback terminal function contains two FEs: Audience's selection options management FE and Video play FE. An Audience is shown interacting with a computer. Information flows are indicated by arrows: I\_CO-CS (bidirectional) between Camera objects and Camera control server; I\_CO-VP (bidirectional) between Camera objects and Video playback terminal; I\_VP-CS (bidirectional) between Video playback terminal and Camera control server; and I\_VP-AU (bidirectional) between Video playback terminal and Audience. A reference point Y.4412-F.747.8(15)\_F02 is noted near the Audience.
+
+**Figure 2 – Reference architecture of ASM service framework**
+
+As shown in Figure 2, there are three ASM service framework functions: camera objects function, camera control server function and video playback terminal function. Each function is described as follows in terms of supported functions, supported information, and supported FEs:
+
+- **camera objects function:** A camera objects function tracks an object of interest, communicates the updated status of the object of interest to the camera control server function, and transmits the audience-selected video to the video playback terminal function. Based on these functional descriptions, the camera objects function includes three FEs of object of interest processing, communication, and video transmission;
+- **camera control server function:** The camera control server function manages the main camera object based on the audience's selection, updates the camera object group based on the tracking result of the object of interest, and controls each camera object using the calculated pan, tilt, and, zoom values. Camera control server function contains three FEs of main camera object management, camera object group management, and camera pan-tilt-zoom control;
+- **video playback terminal function:** Video playback terminal function receives the audience's selection options, transmits the audience's selection information to the camera objects function and camera control sever function, and plays the audience-selected video. The video playback terminal function consists of two FEs of the audience's selection management and video play.
+
+As illustrated in Figure 2, there are four reference points:  $I_{CO-CS}$ ,  $I_{CO-VP}$ ,  $I_{VP-CS}$ , and  $I_{VP-AU}$  as follows:
+
+- **$I_{CO-CS}$ :**  $I_{CO-CS}$  is a reference point between the camera objects function and the camera control server function. The position of the object of interest is transferred from the camera objects function to the camera control server function. On the other hand, updated information, including object of interest selection, main camera object selection, camera object group selection, and camera control (e.g., pan, tilt, and zoom values of each camera object) information is transferred from the camera control server function to camera objects function;
+- **$I_{CO-VP}$ :**  $I_{CO-VP}$  is a reference point between the camera object function and video playback terminal function. The camera objects function sends the audience-selected video to the video playback terminal function. Also, the playback terminal function sends the audience's selection information and playing options to the camera objects function;
+
+- **IVP-CS:** IVP-CS is a reference point between the video playback terminal function and camera control server function. Through this reference point, video playback terminal transfers the audience's selection information and playing options to the camera control server function. Also, the video playback terminal function transmits the updated information, including the main camera object selection information (for each camera object group), camera object group selection information (for each object of interest), and camera control information for each camera object to the camera control server function;
+- **IVP-AU:** IVP-AU is a reference point between the video playback terminal function and the audience. The video playback terminal function shows a list of the audience's selection options available to the audience. The video playback terminal function then receives the audience's selection information and playing options from the audience. Through this reference point, the video playback terminal function shows the current status of each camera object group, current camera control status of each camera object, currently-selected main camera object, position of each object of interest, multi-camera video thumbnails, and audience-selected video with selected playing options during the service.
+
+### **8.2 Camera objects function**
+
+The camera objects function:
+
+- consists of object of interest processing, communication, and video transmission FEs.
+
+#### **8.2.1 Object of interest processing FE**
+
+The object of interest processing FE:
+
+- obtains the ID and the position or the tracking result of the audience-selected object of interest in each captured frame through object of interest extraction and tracking;
+- identifies an object of interest in order to provide positional information of each object of interest that is used for generating and updating its corresponding camera object group in camera control server function;
+- converts the tracked position of the audience-selected object of interest in the main camera object to the position in each frame captured by its sub-camera object using the camera position and pose information.
+
+#### **8.2.2 Communication FE**
+
+The communications FE:
+
+- transmits the ID and the positions or the tracking results of an audience-selected object of interest in each captured frame to the other sub-camera objects and the camera control server function when one of the camera object functions is selected as a main camera object;
+- receives the positions or the tracking result of the audience-selected object of interest in each frame of the main camera object when one of the camera objects is selected as a sub-camera object;
+- receives the audience's selection information such as an object of interest selection, a main camera object selection in a camera object group, a selection of an interested camera object among multi-camera objects, video playback terminal selection, and camera object group selection from the video playback terminal function;
+- receives the camera control information such as pan-tilt-zoom values from camera pan-tilt-zoom control FE of the camera control server function.
+
+#### **8.2.3 Video transmission FE**
+
+The video transmission FE:
+
+- transmits a video stream of the main camera object selected by audience to the video playback terminal function.
+
+### **8.3 Camera control server function**
+
+The camera control server function:
+
+- consists of main camera object management, camera object group management, and optional camera pan-tilt-zoom control FEs.
+
+#### **8.3.1 Main camera object management FE**
+
+The main camera object management FE:
+
+- receives the audience's main camera object selection information from the video playback terminal function;
+- updates the main camera object candidates in each camera object group for updating based on the tracking results of the audience-selected object of interest transmitted from the object of interest processing FE within appropriate intervals;
+- recommends the main camera object candidates in each camera object group to the audiences based on the tracking results of the object of interest when the main camera object needs to be updated;
+- notifies the audience's selection to the newly audience-selected main camera object in order to track the selected object of interest and transmit an audience-selected video when the audience's main camera object selection information is updated from the video playback terminal function.
+
+#### **8.3.2 Camera object group management FE**
+
+The camera object group management FE:
+
+- initially generates camera object groups according to each identified object of interest;
+- classifies each camera object into its corresponding camera object group according to the existence of identified objects of interest in camera objects;
+- receives the position or the tracking result of the audience-selected object of interest in each frame from all the camera objects in the group within appropriate time interval;
+- updates the members of each camera object group based on the tracking result of each audience-selected object of interest;
+- notifies member updates in each camera object group to the audiences.
+
+#### **8.3.3 Camera pan-tilt-zoom control FE**
+
+The camera pan-tilt-zoom control FE:
+
+- calculates pan, tilt, and zoom values of each sub-camera object according to the position and the size of the object of interest in the frame of the main camera object in order to make camera objects within the same camera object group look at the same object of interest;
+- transmits the calculated pan, tilt, and zoom values of sub-camera objects to each corresponding sub-camera object within the same camera object group in order to control the sub-camera objects, respectively.
+
+### **8.4 Video playback terminal function**
+
+The video playback terminal function:
+
+- consists of the audience's selection options management and video play FEs.
+
+#### **8.4.1 Audience's selection options management FE**
+
+The audience's selection options management FE:
+
+- shows a list of available audience selection options to the audience;
+- receives audience's selection information from the audience;
+- transmits audience's selection information to the camera control server function;
+- transmits audience's selection information to each camera object function;
+- includes options of an object of interest selection, a main camera object selection, and a selection of interested camera objects among multi-camera objects providing different views;
+- includes the audience's choices among available audience selection options.
+
+#### **8.4.2 Video play FE**
+
+The video play FE:
+
+- receives an audience-selected video from the camera object function;
+- shows a current status of each camera object group, a current camera control status of each camera object, a currently-selected main camera object, the position of each object of interest, multi-camera video thumbnails, and an audience-selected video with audience-selected playing options;
+- plays an audience-selected video;
+- controls a playing status of the current audience-selected video with audience-selected playing options.
+
+# Appendix I
+
+## Use cases for ASM service
+
+(This appendix does not form an integral part of this Recommendation.)
+
+### I.1 Use case for an ASM broadcasting service using multi-camera objects
+
+Figure I.1 shows a use case for an ASM broadcasting service using multi-camera objects. This use case provides audiences with a selection option of choosing a video media from one camera object amongst multi-camera objects that capture a person (an object of interest) whom an audience is interested in. It also provides a selection option of switching a video media from one camera object to another camera object.
+
+![Figure I.1 - Use case for ASM broadcasting service using multi-camera objects](fc857414626a8d94d132e12d9afe52a4_img.jpg)
+
+The diagram illustrates the workflow of an ASM broadcasting service. At the top, a 'Broadcaster' icon is shown. Arrows labeled (2) point to three 'Camera object groups' (COG): 'COG 1 for P1', 'COG 2 for P2', and 'COG for P3'. Each COG contains multiple camera icons (e.g., (10), (11)) connected by double-headed arrows indicating 'Sharing of object of interest position by cam-to-cam communication'. A 'Camera control server object' is connected to these groups via arrow (12). Below the COGs, a sports arena image shows players P1, P2, and P3, with camera labels A-F and X-Z. Arrow (9) connects COGs to this scene. An 'Audience' icon is shown on the left, interacting with a 'Video streaming server object' via arrows (3), (4), (5), (6), (8). Arrow (1) connects the Broadcaster to the Audience. At the bottom, two 'Main Camera' views are shown: one for P1 (yellow) and one for P3 (red), displaying the selected player and thumbnail options for other cameras (Cam A, B, C for P1; Cam V, W, Z for P3). A legend indicates solid arrows for 'Inclusion of camera object' and dashed arrows for 'Exclusion of camera object'.
+
+Figure I.1 - Use case for ASM broadcasting service using multi-camera objects
+
+**Figure I.1 – Use case for ASM broadcasting service using multi-camera objects**
+
+In this use case, there is the assumption that each audience has its own object of interest (e.g., a person such as a sports player or famous actress or actor) in the broadcasted video and each object of interest appears and disappears in some camera objects and frames.
+
+- (1) broadcasters predefine object of interest candidates (e.g., sports players) that will appear in the scene that they are going to broadcast;
+- (2) broadcasters generate camera object groups by combining suitable multi-camera objects that capture candidate objects of interest among available camera objects located at the site where broadcasters want to broadcast;
+- (3) broadcasters show videos or thumbnail images captured by each camera object group to the audiences;
+- (4) an audience selects one camera object group that captures an object of interest that he or she is interested in among multi-camera object groups;
+- (5) the audience also selects a main camera object among multi-camera objects in the selected camera object group;
+
+10 Rec. ITU-T Y.4412/F.747.8 (11/2015)
+
+- (6) the audience also selects a region of interest that includes an object of interest in the main camera object image;
+- (7) video streaming server object streams and shows a video of the main camera object with sub-images (e.g., thumbnails) of other camera objects to the audience;
+- (8) during the streaming, the audiences may switch the main camera object to another camera object if he or she wants to watch the video with a different camera angle;
+- (9) after the object of interest selection, a video processing server object that is linked with the main camera object starts the video processing, such as automatic tracking of a selected object of interest in the main camera object frame by frame;
+- (10) during the tracking process, the main camera object transmits a tracked position of the selected object of interest to the other camera objects by camera-to-camera transmission;
+- (11) the other camera objects receive and calculate the position of the selected object of interest from the received tracked position in the image of the main camera object;
+- (12) based on each calculated position of an object of interest in each camera object, the camera object control server object updates the component camera objects in each camera object group;
+- (13) the process repeats step 4) to step 13) until the audiences or the broadcasters quit the current media service.
+
+Finally, each audience can enjoy personalized video media content that includes an object of interest and has a camera view that each audience wants to watch.
+
+### **I.2 Use case for an open screen service using multi-camera objects**
+
+Open screen service can be a use case of the ASM service. Open screen service is a service based on open platform to control various types of screens and to show content by sensing states (e.g., age and gender) and movement of a human being. Representative use cases of open screen service include digital signage and emergency service. For example, if a person is near a screen using open platform of open screen service, the screen can show an image or video media advertisement or an evacuation route to the person.
+
+In order to sense states and movement of human beings, multi-camera objects and camera control servers are mandatory for the open screen service. In the perspective of open screen service, the audience can be an advertiser or emergency service provider, and the object of interest can be a human being who is a customer of an advertiser.
+
+Figure I.2 explains use case for an open screen service using multi-camera objects:
+
+- (1) an object of interest (e.g., customer) moves to the vicinity of a screen (e.g., screen 1) equipped with a camera object (e.g., camera object 1).
+- (2) The camera object (e.g., camera object 1) captures video data of the object of interest and then sends the captured video data to camera control server.
+- (3) The camera control server sends information for tracking the object of interest to the camera object (e.g., camera object 1).
+- (4) The camera control server sends the position information and captured video data to media server being owned by the audience (e.g., advertiser) and providing image or video media (e.g., advertisement) that the audience (e.g., advertiser) wants to provide for the object of interest (e.g., customer).
+
+- (5) The media server determines images or video media (e.g., advertisements) that the audience wants to provide for the object of interest (e.g., customer), and then provides the media to the screen (e.g., screen 1). Interaction between camera objects can include information for supporting the camera's tracking the object of interest. The information for tracking the object of interest can include position information for where the object of interest is located.
+
+![Diagram illustrating the use case for an open screen service using multi-camera objects, camera control server, and media server.](ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg)
+
+The diagram illustrates a system architecture for an open screen service. It includes the following components and interactions:
+
+- Media server:** A server that provides media content to the screens.
+- Audience (e.g., advertiser):** Represented by a building icon, it interacts with the Media server.
+- Camera control server:** A server that manages the camera objects.
+- Camera object 1, 2, 3:** Represented by camera icons, they interact with the Camera control server and the Media server.
+- Screen 1, 2, 3:** Represented by TV icons, they display content. Screen 1 is red, Screen 2 and 3 show a soda bottle.
+- Object of interest (e.g., customer):** Represented by a person icon, they are tracked by the camera objects.
+
+Numbered interactions (1-5) are shown:
+
+- A green arrow (1) points from Screen 2 to Screen 3.
+- A black arrow (2) points from Camera object 2 to the Camera control server.
+- A black arrow (3) points from the Media server to Camera object 1.
+- A blue arrow (4) points from the Camera control server to the Media server.
+- A red arrow (5) points from the Media server to Screen 1.
+
+Additional labels and connections:
+
+- A dashed purple double-headed arrow connects Camera object 1 and Camera object 2.
+- A dashed purple double-headed arrow connects Camera object 2 and Camera object 3.
+- A purple arrow points from the Object of interest to Camera object 1.
+- A purple arrow points from the Object of interest to Camera object 2.
+- A purple arrow points from the Object of interest to Camera object 3.
+- A red arrow points from the Media server to Screen 1.
+- A red arrow points from the Media server to Screen 2.
+- A red arrow points from the Media server to Screen 3.
+
+Y.4412-F.747.8(15)\_FI.2
+
+Diagram illustrating the use case for an open screen service using multi-camera objects, camera control server, and media server.
+
+**Figure I.2 – Use case for an open screen service using multi-camera objects, camera control server and media server**
+
+## Bibliography
+
+- [b-ITU-T Y.2002] Recommendation ITU-T Y.2002 (2009), *Overview of ubiquitous networking and of its support in NGN*.
+- [b-ITU-T Y.4000] Recommendation ITU-T Y.4000/Y.2060 (2012), *Overview of the Internet of Things*.
+- [b-ITU-T Y.4400] Recommendation ITU-T Y.4400/Y.2063 (2012), *Framework of Web of Things*.
+
+
+
+## ITU-T F-SERIES RECOMMENDATIONS NON-TELEPHONE TELECOMMUNICATION SERVICES
+
+|                                                                 |                    |
+|-----------------------------------------------------------------|--------------------|
+| TELEGRAPH SERVICE                                               |                    |
+| Operating methods for the international public telegram service | F.1–F.19           |
+| The gentex network                                              | F.20–F.29          |
+| Message switching                                               | F.30–F.39          |
+| The international telemesssage service                          | F.40–F.58          |
+| The international telex service                                 | F.59–F.89          |
+| Statistics and publications on international telegraph services | F.90–F.99          |
+| Scheduled and leased communication services                     | F.100–F.104        |
+| Phototelegraph service                                          | F.105–F.109        |
+| MOBILE SERVICE                                                  |                    |
+| Mobile services and multideestination satellite services        | F.110–F.159        |
+| TELEMATIC SERVICES                                              |                    |
+| Public facsimile service                                        | F.160–F.199        |
+| Teletex service                                                 | F.200–F.299        |
+| Videotex service                                                | F.300–F.349        |
+| General provisions for telematic services                       | F.350–F.399        |
+| MESSAGE HANDLING SERVICES                                       | F.400–F.499        |
+| DIRECTORY SERVICES                                              | F.500–F.549        |
+| DOCUMENT COMMUNICATION                                          |                    |
+| Document communication                                          | F.550–F.579        |
+| Programming communication interfaces                            | F.580–F.599        |
+| DATA TRANSMISSION SERVICES                                      | F.600–F.699        |
+| <b>AUDIOVISUAL SERVICES</b>                                     | <b>F.700–F.799</b> |
+| ISDN SERVICES                                                   | F.800–F.849        |
+| UNIVERSAL PERSONAL TELECOMMUNICATION                            | F.850–F.899        |
+| HUMAN FACTORS                                                   | F.900–F.999        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                                           |
+|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                                                         |
+| Series D        | General tariff principles                                                                                                                                 |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                                                         |
+| <b>Series F</b> | <b>Non-telephone telecommunication services</b>                                                                                                           |
+| Series G        | Transmission systems and media, digital systems and networks                                                                                              |
+| Series H        | Audiovisual and multimedia systems                                                                                                                        |
+| Series I        | Integrated services digital network                                                                                                                       |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                                               |
+| Series K        | Protection against interference                                                                                                                           |
+| Series L        | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant |
+| Series M        | Telecommunication management, including TMN and network maintenance                                                                                       |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                                           |
+| Series O        | Specifications of measuring equipment                                                                                                                     |
+| Series P        | Terminals and subjective and objective assessment methods                                                                                                 |
+| Series Q        | Switching and signalling                                                                                                                                  |
+| Series R        | Telegraph transmission                                                                                                                                    |
+| Series S        | Telegraph services terminal equipment                                                                                                                     |
+| Series T        | Terminals for telematic services                                                                                                                          |
+| Series U        | Telegraph switching                                                                                                                                       |
+| Series V        | Data communication over the telephone network                                                                                                             |
+| Series X        | Data networks, open system communications and security                                                                                                    |
+| Series Y        | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities                               |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                                                      |

marked/Y/T-REC-H.642.1-201206-I_PDF-E/raw.md

@@ -0,0 +1,516 @@
+
+
+I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n
+
+# ITU-T
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+# H.642.1
+
+(06/2012)
+
+SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS
+
+Broadband, triple-play and advanced multimedia  
+services – Ubiquitous sensor network applications and  
+Internet of Things
+
+# --- **Multimedia information access triggered by tag-based identification – Identification scheme**
+
+Recommendation ITU-T H.642.1
+
+![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg)
+
+The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a red lightning bolt striking it, and the text "ITU" in blue, with "International Telecommunication Union" in smaller blue text below it.
+
+ITU logo
+
+## ITU-T H-SERIES RECOMMENDATIONS AUDIOVISUAL AND MULTIMEDIA SYSTEMS
+
+|                                                                               |                    |
+|-------------------------------------------------------------------------------|--------------------|
+| CHARACTERISTICS OF VISUAL TELEPHONE SYSTEMS                                   | H.100–H.199        |
+| INFRASTRUCTURE OF AUDIOVISUAL SERVICES                                        |                    |
+| General                                                                       | H.200–H.219        |
+| Transmission multiplexing and synchronization                                 | H.220–H.229        |
+| Systems aspects                                                               | H.230–H.239        |
+| Communication procedures                                                      | H.240–H.259        |
+| Coding of moving video                                                        | H.260–H.279        |
+| Related systems aspects                                                       | H.280–H.299        |
+| Systems and terminal equipment for audiovisual services                       | H.300–H.349        |
+| Directory services architecture for audiovisual and multimedia services       | H.350–H.359        |
+| Quality of service architecture for audiovisual and multimedia services       | H.360–H.369        |
+| Supplementary services for multimedia                                         | H.450–H.499        |
+| MOBILITY AND COLLABORATION PROCEDURES                                         |                    |
+| Overview of Mobility and Collaboration, definitions, protocols and procedures | H.500–H.509        |
+| Mobility for H-Series multimedia systems and services                         | H.510–H.519        |
+| Mobile multimedia collaboration applications and services                     | H.520–H.529        |
+| Security for mobile multimedia systems and services                           | H.530–H.539        |
+| Security for mobile multimedia collaboration applications and services        | H.540–H.549        |
+| Mobility interworking procedures                                              | H.550–H.559        |
+| Mobile multimedia collaboration inter-working procedures                      | H.560–H.569        |
+| BROADBAND, TRIPLE-PLAY AND ADVANCED MULTIMEDIA SERVICES                       |                    |
+| Broadband multimedia services over VDSL                                       | H.610–H.619        |
+| Advanced multimedia services and applications                                 | H.620–H.629        |
+| <b>Ubiquitous sensor network applications and Internet of Things</b>          | <b>H.640–H.649</b> |
+| IPTV MULTIMEDIA SERVICES AND APPLICATIONS FOR IPTV                            |                    |
+| General aspects                                                               | H.700–H.719        |
+| IPTV terminal devices                                                         | H.720–H.729        |
+| IPTV middleware                                                               | H.730–H.739        |
+| IPTV application event handling                                               | H.740–H.749        |
+| IPTV metadata                                                                 | H.750–H.759        |
+| IPTV multimedia application frameworks                                        | H.760–H.769        |
+| IPTV service discovery up to consumption                                      | H.770–H.779        |
+| Digital Signage                                                               | H.780–H.789        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+# **Recommendation ITU-T H.642.1**
+
+# **Multimedia information access triggered by tag-based identification – Identification scheme**
+
+## **Summary**
+
+Recommendation ITU-T H.642.1 defines an identification scheme for multimedia information access triggered by tag-based identification. Multimedia information associated with such an identifier can be retrieved using a resolution process.
+
+This Recommendation provides a framework for accommodating the legacy existing identification schemes together with the new identification scheme defined here using a pair of object identifiers for the identification scheme and identifier itself.
+
+## **History**
+
+| Edition | Recommendation | Approval   | Study Group |
+|---------|----------------|------------|-------------|
+| 1.0     | ITU-T H.642.1  | 2012-06-29 | 16          |
+
+## **Keywords**
+
+Identification scheme, identifier.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>.
+
+© ITU 2013
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## Table of Contents
+
+|   |                                                                                                                           | <b>Page</b> |
+|---|---------------------------------------------------------------------------------------------------------------------------|-------------|
+| 1 | Scope .....                                                                                                               | 1           |
+| 2 | References.....                                                                                                           | 1           |
+| 3 | Definitions .....                                                                                                         | 1           |
+|   | 3.1 Terms defined elsewhere.....                                                                                          | 1           |
+|   | 3.2 Terms defined in this Recommendation.....                                                                             | 2           |
+| 4 | Abbreviations and acronyms .....                                                                                          | 2           |
+| 5 | Conventions .....                                                                                                         | 3           |
+| 6 | Concept of an identification scheme for multimedia information access triggered by tag-based identification.....          | 3           |
+|   | 6.1 Overview .....                                                                                                        | 3           |
+|   | 6.2 Uniqueness of ID value .....                                                                                          | 3           |
+| 7 | ITU-T H.642 identification scheme for multimedia information access triggered by tag-based identification.....            | 4           |
+|   | 7.1 Structure of an ITU-T H.642 identification scheme.....                                                                | 4           |
+|   | 7.2 First level code .....                                                                                                | 5           |
+|   | 7.3 Second level code (2LC) .....                                                                                         | 5           |
+|   | 7.4 Class .....                                                                                                           | 5           |
+|   | 7.5 Third level code (3LC) .....                                                                                          | 5           |
+|   | 7.6 Fourth level code (4LC) .....                                                                                         | 5           |
+|   | Appendix I – Survey on identification schemes .....                                                                       | 6           |
+|   | I.1 Introduction .....                                                                                                    | 6           |
+|   | I.2 Need for a generic identification scheme for multimedia information access triggered by tag-based identification..... | 6           |
+|   | I.3 Requirements on the identifier for multimedia information access triggered by tag-based identification.....           | 6           |
+|   | I.4 Survey on existing identification schemes .....                                                                       | 7           |
+|   | Bibliography.....                                                                                                         | 11          |
+
+## **Introduction**
+
+The identification scheme defined in this Recommendation provides a new method for accessing multimedia content without typing its address on a keyboard or inputting the name of objects and/or places of relevant information. This is a major communication service that uses an identifier in data carriers such as radio frequency identifications (RFIDs), smart cards and barcodes.
+
+The purpose of this Recommendation is to specify a new identification scheme to be used in applications and services where the existing identification schemes and their combinations cannot be used (see Appendix I for some examples).
+
+From the standpoint of compatibility and reusability of existing identifier schemes, this Recommendation provides a framework to support multiple identification schemes. In this framework, it is possible that multiple existing identification schemes together with the proposed new identification scheme can be used for identification where appropriate. Each identification scheme is identified by an object identifier (OID) according to [ITU-T X.660].
+
+Clause 6 introduces the concept of multiple identification schemes for multimedia information access triggered by tag-based identification.
+
+Clause 7 specifies a new generic identification scheme for multimedia information access triggered by tag-based identification.
+
+Appendix I provides additional information which explains why a new generic identification scheme is needed.
+
+## Recommendation ITU-T H.642.1
+
+# Multimedia information access triggered by tag-based identification – Identification scheme
+
+# 1 Scope
+
+This Recommendation defines an identification scheme for multimedia information access triggered by tag-based identification. This identification scheme is mainly used in the multimedia information system architecture defined in [ITU-T H.621]. It also satisfies the requirements defined in [ITU-T F.771].
+
+This Recommendation does not define encoding rules to store the identifier value into data carriers such as barcode tags and RFID tags. When stored in a data carrier, the OID and identifier value shall be encoded according to the relevant international standards if such standards exist for the type of data carrier.
+
+# 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation.
+
+- [ITU-T F.771] Recommendation ITU-T F.771 (2008), *Service description and requirements for multimedia information access triggered by tag-based identification*.
+- [ITU-T H.621] Recommendation ITU-T H.621 (2008), *Architecture of a system for multimedia information access triggered by tag-based identification*.
+- [ITU-T H.642.2] Recommendation ITU-T H.642.2 (2012), *Multimedia information access triggered by tag-based identification – Registration procedures for identifiers*.
+- [ITU-T X.660] Recommendation ITU-T X.660 (2011) | ISO/IEC 9834-1:2012, *Information technology – Procedures for the operation of object identifier registration authorities: General procedures and top arcs of the international object identifier tree*.
+- [ITU-T X.668] Recommendation ITU-T X.668 (2008) | ISO/IEC 9834-9:2008, *Information technology – Open Systems Interconnection – Procedures for the operation of OSI Registration Authorities: Registration of object identifier arcs for applications and services using tag-based identification*.
+
+# 3 Definitions
+
+### 3.1 Terms defined elsewhere
+
+This Recommendation uses the following terms defined elsewhere:
+
+**3.1.1 ID resolution** [ITU-T F.771]: A function to resolve an identifier into associated information.
+
+**3.1.2 multimedia information** [ITU-T F.771]: Digital information that uses multiple forms of information content and information processing, such as text, pictures, audio, video, three-dimensional panoramic pictures and digital maps, which informs or entertains users.
+
+**3.1.3 object identifier** [b-ITU-T X.680]: A globally unique value associated with an object to unambiguously identify it.
+
+### **3.2 Terms defined in this Recommendation**
+
+This Recommendation defines the following terms:
+
+**3.2.1 class**: Part of an identifier that defines the layout and interpretation of the following bit string inside the identifier, especially the length of the third level code (3LC) and fourth level code (4LC).
+
+**3.2.2 first level code (1LC)**: Part of the identifier that represents the identifier sub-blocks.
+
+**3.2.3 fourth level code (4LC)**: Part of the identifier which serializes individual multimedia information and services.
+
+**3.2.4 ITU-T H.642 identification scheme**: Name given to the identification scheme defined in this Recommendation.
+
+**3.2.5 identification scheme**: Definition and description of the structure of identifiers.
+
+**3.2.6 identifier value**: String of characters that represents the value of the identifier.
+
+**3.2.7 second level code (2LC)**: Part of the identifier assigned to ITU Member States.
+
+**3.2.8 third level code (3LC)**: Part of the identifier assigned to an RA that handles the allocation of the subspace to other organizations.
+
+# **4 Abbreviations and acronyms**
+
+This Recommendation uses the following abbreviations and acronyms:
+
+|       |                                      |
+|-------|--------------------------------------|
+| 1LC   | First Level Code                     |
+| 2LC   | Second Level Code                    |
+| 3LC   | Third Level Code                     |
+| 4LC   | Fourth Level Code                    |
+| EPC   | Electronic Product Code              |
+| GIAI  | Global Individual Asset Identifier   |
+| GRAI  | Global Returnable Asset Identifier   |
+| ID    | Identifier                           |
+| IP    | Internet Protocol                    |
+| ISBN  | International Standard Book Number   |
+| ISSN  | International Standard Serial Number |
+| OID   | Object Identifier                    |
+| RA    | Registration Authority               |
+| RFID  | Radio Frequency Identification       |
+| SGLN  | Serialized Global Location Number    |
+| SGTIN | Serialized Global Trade Item Number  |
+
+|      |                                |
+|------|--------------------------------|
+| SSCC | Serial Shipping Container Code |
+| URL  | Uniform Resource Locator       |
+| URN  | Uniform Resource Name          |
+| UUID | Universally Unique Identifier  |
+
+# 5 Conventions
+
+In this Recommendation,  $xx_2$  denotes that number  $xx$  is expressed as a binary (base-2) number.
+
+# 6 Concept of an identification scheme for multimedia information access triggered by tag-based identification
+
+### 6.1 Overview
+
+An identification scheme in this Recommendation is designed to discriminate multimedia information and services associated with "objects" or "places" of the real world in the architecture defined by [ITU-T H.621].
+
+A data carrier such as an RFID tag which triggers access can be placed anywhere and its whereabouts is out of the scope of this Recommendation.
+
+### 6.2 Uniqueness of ID value
+
+Figure 1 gives an overview of the general approach to accommodate multiple identification schemes. Many different identification schemes can be used for multimedia information access triggered by tag-based identification. Each identification scheme should be identified by an object identifier (OID) under the arc  $\{\text{joint-iso-itu-t}(2) \text{ tag-based}(27)\}$  as specified in [ITU-T X.668]. For example, in Figure 1, the top row indicates that Identification scheme 1 is identified by OID arch  $\{\text{joint-iso-itu-t}(2) \text{ tag-based}(27) i_1\}$ .
+
+Identifier schemes which are widely used and already have an OID allocated to them (not under arc  $\{\text{joint-iso-itu-t}(2) \text{ tag-based}(27)\}$ ) can continue to use that OID. In Figure 1, "Existing identification scheme 1", that has an OID value not under arc  $\{\text{joint-iso-itu-t}(2) \text{ tag-based}(27)\}$  is identified by OID  $\{x_1 y_1 z_1\}$ .
+
+For a given identifier scheme (identified by an OID), the uniqueness of identifier values is required to be managed by the organization which is allocating those values. That is, the uniqueness of identifier values should be managed by the registration authority (RA) for that identifier scheme with the cooperation of those who store identifiers into data carriers.
+
+![Diagram showing multiple identification schemes. It consists of four rows. The first row shows 'OID:2.27.i1' in a box, followed by a plus sign, and then 'Identification scheme 1' in a box. The second row shows a vertical ellipsis in the first column and a vertical ellipsis in the second column. The third row shows 'OID:2.27.im' in a box, followed by a plus sign, and then 'Identification scheme m' in a box. The fourth row shows a vertical ellipsis in the first column and a vertical ellipsis in the second column. The fifth row shows 'OID:x1.y1.z1' in a box, followed by a plus sign, and then 'Existing Identification scheme 1' in a box. The sixth row shows a vertical ellipsis in the first column and a vertical ellipsis in the second column. The seventh row shows 'OID:xN.yN.zN' in a box, followed by a plus sign, and then 'Existing Identification scheme N' in a box.](0bf9346902e9a3bdabf05ceacc1947f5_img.jpg)
+
+|                                                    |   |                                  |
+|----------------------------------------------------|---|----------------------------------|
+| OID:2.27.i <sub>1</sub>                            | + | Identification scheme 1          |
+| ⋮                                                  |   | ⋮                                |
+| OID:2.27.i <sub>m</sub>                            | + | Identification scheme m          |
+| ⋮                                                  |   | ⋮                                |
+| OID:x <sub>1</sub> .y <sub>1</sub> .z <sub>1</sub> | + | Existing Identification scheme 1 |
+| ⋮                                                  |   | ⋮                                |
+| OID:x <sub>N</sub> .y <sub>N</sub> .z <sub>N</sub> | + | Existing Identification scheme N |
+
+Diagram showing multiple identification schemes. It consists of four rows. The first row shows 'OID:2.27.i1' in a box, followed by a plus sign, and then 'Identification scheme 1' in a box. The second row shows a vertical ellipsis in the first column and a vertical ellipsis in the second column. The third row shows 'OID:2.27.im' in a box, followed by a plus sign, and then 'Identification scheme m' in a box. The fourth row shows a vertical ellipsis in the first column and a vertical ellipsis in the second column. The fifth row shows 'OID:x1.y1.z1' in a box, followed by a plus sign, and then 'Existing Identification scheme 1' in a box. The sixth row shows a vertical ellipsis in the first column and a vertical ellipsis in the second column. The seventh row shows 'OID:xN.yN.zN' in a box, followed by a plus sign, and then 'Existing Identification scheme N' in a box.
+
+Figure 1 – Multiple identification schemes
+
+# **7 ITU-T H.642 identification scheme for multimedia information access triggered by tag-based identification**
+
+### **7.1 Structure of an ITU-T H.642 identification scheme**
+
+The identification scheme defined in this Recommendation is called the ITU-T H.642 identification scheme. The ITU-T H.642 identification scheme consists of the fields: 'First Level Code' (1LC), 'Second Level Code' (2LC) and 'Class', followed by some of the elements ('Third Level Code' (3LC) and 'Fourth Level Code' (4LC)) as shown in Figure 2.
+
+| 1LC                                         | 2LC                                                  | CLASS             | 3LC / 4LC |         |     |     |     |     |     |  |  |  |  |  |  |  |
+|---------------------------------------------|------------------------------------------------------|-------------------|-----------|---------|-----|-----|-----|-----|-----|--|--|--|--|--|--|--|
+| 4 bits                                      | 16 bits                                              | 4 bits            | 8 bits    | 16 bits | 16  | 16  | 16  | 16  | 16  |  |  |  |  |  |  |  |
+| 0001 <sub>2</sub>                           | 16 bits                                              | 0000 <sub>2</sub> | Reserved  |         |     |     |     |     |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 0001 <sub>2</sub> | Reserved  |         |     |     |     |     |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 0010 <sub>2</sub> | Reserved  |         |     |     |     |     |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 0011 <sub>2</sub> | Reserved  |         |     |     |     |     |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 0100 <sub>2</sub> | Reserved  |         |     |     |     |     |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 0101 <sub>2</sub> | Reserved  |         |     |     |     |     |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 0110 <sub>2</sub> | Reserved  |         |     |     |     |     |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 0111 <sub>2</sub> | Reserved  |         |     |     |     |     |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 1000 <sub>2</sub> | Reserved  |         |     |     |     |     |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 1001 <sub>2</sub> | 3LC       | 4LC     |     |     |     |     |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 1010 <sub>2</sub> | 3LC       |         | 4LC |     |     |     |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 1011 <sub>2</sub> | 3LC       |         |     | 4LC |     |     |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 1100 <sub>2</sub> | 3LC       |         |     |     | 4LC |     |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 1101 <sub>2</sub> | 3LC       |         |     |     |     | 4LC |     |  |  |  |  |  |  |  |
+|                                             |                                                      | 1110 <sub>2</sub> | 3LC       |         |     |     |     |     | 4LC |  |  |  |  |  |  |  |
+|                                             |                                                      | 1111 <sub>2</sub> | Reserved  |         |     |     |     |     |     |  |  |  |  |  |  |  |
+| 0000 <sub>2</sub>                           | Reserved for backward compatibility (see clause 7.2) |                   |           |         |     |     |     |     |     |  |  |  |  |  |  |  |
+| 0010 <sub>2</sub><br>~<br>1111 <sub>2</sub> | Reserved for future use                              |                   |           |         |     |     |     |     |     |  |  |  |  |  |  |  |
+
+**Figure 2 – Structure of an identifier**
+
+**Table 1 – Field name and length**
+
+| Field name | Length                                            |               |               |
+|------------|---------------------------------------------------|---------------|---------------|
+| 1LC        | 4 bits                                            |               |               |
+| 2LC        | 16 bits                                           |               |               |
+| CLASS      | 4 bits                                            |               |               |
+| 3LC, 4LC   | Variable length, but the sum of these is 104 bits |               |               |
+|            | Value of class                                    | Length of 3LC | Length of 4LC |
+|            | 9                                                 | 8 bits        | 96 bits       |
+|            | 10                                                | 24 bits       | 80 bits       |
+|            | 11                                                | 40 bits       | 64 bits       |
+|            | 12                                                | 56 bits       | 48 bits       |
+|            | 13                                                | 72 bits       | 32 bits       |
+|            | 14                                                | 88 bits       | 16 bits       |
+
+### **7.2 First level code**
+
+1LC is 4 bits long and represents the identifier of sub-blocks. It serves as version information.
+
+1LC from 0010<sub>2</sub> to 1111<sub>2</sub> are reserved for future use.
+
+Part of the identifier sub-block with 1LC of 0000<sub>2</sub> shall be reserved to avoid conflict with the 'unicode' identification scheme [b-uID].
+
+### **7.3 Second level code (2LC)**
+
+2LC is 16 bits long and is assigned to ITU Member States as specified in [ITU-T H.642.2].
+
+### **7.4 Class**
+
+Class indicates the layout of a particular identifier format. There are different formats that correspond to Class 9, 10..., 14 as shown on Figure 2 (Class 0, 1, 2..., 8, 15 are reserved for future use).
+
+### **7.5 Third level code (3LC)**
+
+The 3LC assignment is done by an entity that is assigned the 2LC of that subspace (see clause 7.3). A 3LC is assigned to an RA that handles the allocation of the subspace to other organizations. The subspace controlled by this RA is called the 3LC space. It has six different sizes from 16 bits to 96 bits by steps of 16 bits.
+
+3LC spaces are assumed to be managed by entities such as companies, associations, universities, schools, local governments, etc.
+
+### **7.6 Fourth level code (4LC)**
+
+4LC is a serialization number to identify individual multimedia information and services.
+
+# Appendix I
+
+## Survey on identification schemes
+
+(This appendix does not form an integral part of this Recommendation.)
+
+## I.1 Introduction
+
+The purpose of this appendix is to survey whether existing identification schemes (most of them being internationally standardized) satisfy the requirements found in [ITU-T F.771].
+
+The currently existing schemes may not satisfy all the needs identified by [ITU-T F.771] that came later than the schemes themselves. The ITU-T H.642 identification scheme in this Recommendation is a complementary scheme to existing identification schemes. It is meant to fill the gaps left by existing schemes and identified by [ITU-T F.771] for particular classes of applications. It is complementary to existing schemes in this sense, and is not a competitor. This Recommendation outlines the framework to make these identification schemes co-exist in future applications to take advantage of all the existing schemes including the ITU-T H.642 identification scheme.
+
+## I.2 Need for a generic identification scheme for multimedia information access triggered by tag-based identification
+
+A generic identification scheme in this Recommendation is applicable to multimedia information and services associated with any kind of objects and places. Any systems for multimedia information access triggered by tag-based identification should implement the generic identification scheme defined in this Recommendation.
+
+## I.3 Requirements on the identifier for multimedia information access triggered by tag-based identification
+
+[ITU-T F.771] defines in clause 7.3 five requirements for identifiers for multimedia information access triggered by tag-based identification. The following gives clarification of each identifier requirement to stress that the identification scheme defined in this Recommendation satisfies these identifier requirements.
+
+- **ID-001: identifier is recommended to be used by different applications.**  
+Multimedia information access triggered by tag-based identification specifies a mechanism of information processing and communication, but no applications. The mechanism is proposed and recommended to be used by any application. In other words, it is for "general purpose" use. Also, the identifiers should be for general purposes too. This means, it is recommended to be used by different applications. Most identification schemes can be used for many applications, so almost every identification scheme satisfies this requirement.
+- **ID-002: identifier is required to be assigned for real-world entities such as physical/logical objects, persons and places.**  
+"Tag-based identification" deals with every type of real-world entity e.g. tangible objects (items), persons and places because all of these can be targets of tag-based identification. (Although "people" is mentioned here, this Recommendation does not attempt to define an identifier for persons). In some applications, the information service is triggered by some tangible objects (items), persons or places. Thus, identifiers must be assignable to tangible objects, logical objects, people and places. It is important to note that many application target areas do not have an applicable international standard identification scheme. For example, locations with meanings, vegetables, fish, meat, houses, roads, buildings, bridges, boats, art items, posters and so on, do not have proper identification schemes based on an
+
+international standard. This Recommendation is meant for such wider areas which lack any previous standard ID scheme.
+
+- **ID-003: identifier is required to be issuable by any organization such as companies, non-profit organizations, governments and individual users.**
+
+- ID-003 is a requirement for the governance of identification schemes. To satisfy this requirement, for example, even an individual without any corporate affiliation should be able to obtain identifiers, and identifiers must be allocated at a low enough cost. For example, if an identification scheme has a short company code bit field, and it is too short to be used by all the companies in the country or in the world, it does not satisfy this requirement. If the company code cannot be assigned to non-company organizations such as governments, NPOs, small businesses, schools and individuals, it does not satisfy this requirement. The governance of this Recommendation should satisfy this requirement.
+
+- **ID-004: identifier is required to be globally unique so that the multimedia information access triggered by the identifier is globally available.**
+
+Essentially, the identification scheme proposed must be a globally unique numbering system. When the same identifier is assigned to two different entities, confusion arises. However, some identification schemes do not follow this principle entirely. For example, an IP address system has a private address subspace in its numbering space, such as "192.168.1.1". Everyone can assign the private address to the network interfaces of his/her own networked machines. Some supply chain management (SCM) identification schemes have an "in-house ID code area", which can be used by shops or factories freely, thus the code area is not globally unique. In [b-ITU-T X.667], identifiers are generated automatically by a standard algorithm and procedure, so each identifier is assured to be almost globally unique. However, in theory, there is a small possibility of collisions when random number generators are used. Additionally, there may be bugs in the identifier generating software, and some unauthorised people may intentionally issue duplicate identifiers. Therefore, [b-ITU-T X.667] does not fully satisfy this requirement. The governance of this Recommendation is meant to satisfy this requirement.
+
+- **ID-005: multiple identifier schemes are required to be supported.**
+
+This is an important requirement to accommodate both the existing and the yet-to-appear future identification schemes.
+
+Among the requirements outlined above, ID-005 is not a requirement for the identification scheme itself, but for the system that utilizes identifiers. Therefore, this requirement is excluded from the use case analysis. ID-001 is also excluded from the use case analysis because all the target identification schemes listed below satisfy this requirement.
+
+## **I.4 Survey on existing identification schemes**
+
+#### **I.4.1 Existing identification schemes**
+
+To make this use case analysis comprehensive, widely-used existing identification schemes from a wide range of application areas were studied.
+
+##### **I.4.1.1 EPC**
+
+The electronic product code (EPC) is a family of identification schemes proposed by EPCglobal. It is currently one of the most widely used identification schemes in the field of supply chain management, even though it is not a *de jure* international standard. It is designed to be used in a low-cost way for tracking goods using RFID technology, to meet the needs of various industries, to identify each item manufactured (unlike barcode systems), and to guarantee uniqueness for all EPC-compliant tags. This implies that the initial intention of EPC is to identify products manufactured by using RFID-based tags.
+
+It contains a serialized global trade item number (SGTIN), a serial shipping container code (SSCC), a serialized global location number (SGLN), a global returnable asset identifier (GRAI) and a global individual asset identifier (GIAI).
+
+##### **I.4.1.2 ISO/IEC 15459-x**
+
+[b-ISO/IEC 15459-x] is an identification scheme designed for supply chain management because the original intended application of this identification scheme is for a supply chain management system.
+
+##### **I.4.1.3 ISO/IEC 6709**
+
+[b-ISO/IEC 6709] is an international standard representation of latitude, longitude and altitude for (fixed) geographic point locations. It is used by many GIS applications. But other kinds of ID-based applications such as a supply chain management system, which is intended for the identification of moving objects, cannot use this identification scheme. (It is impractical to replace identifiers whenever objects change their locations. We need a separation of the identifier value and the location information. The multiple identification schemes in [ITU-T H.621] would be effective here).
+
+##### **I.4.1.4 ISO 2108 International standard book number**
+
+The international standard book number (ISBN) is a numbering scheme for the identification of books.
+
+##### **I.4.1.5 ISO 3297 International standard serial number**
+
+The international standard serial number (ISSN) is a numbering scheme for the identification of serial publications such as newspapers, magazines, journals and annually published books globally.
+
+##### **I.4.1.6 Universally unique identifier**
+
+The universally unique identifier (UUID) in [b-ITU-T X.667] is an identification scheme designed for identifying information or components in the distributed systems without the assumption of any management systems of identifiers. One of the most famous implementation of UUID is Microsoft's GUID.
+
+##### **I.4.1.7 ISO/IEC 15963**
+
+[b-ISO/IEC 15963] is an identification scheme designed for RFID tags and mainly used for supply chain management. Since this identification scheme is designed only for RFID tags, it cannot be used for applications that require other kinds of ID tags such as a printing code.
+
+##### **I.4.1.8 ISO/IEC 11784**
+
+[b-ISO/IEC 11784] is an identification scheme designed for identifying animals.
+
+NOTE – All of the above identification schemes other than EPC are *de jure* international standards, and also note that EPC is widely used.
+
+#### **I.4.2 Analysis**
+
+Surveys on existing identification schemes are in Table I.1. For comparison, the ITU-T H.642 identification scheme is also included in this analysis.
+
+**Table I.1 – Analysis of existing identification schemes**
+
+| <b>ID schemes</b> | <b>ID-002</b>                                                                                                                                                                           | <b>ID-003</b>                                                                                                                                                                                                                                                                                                                 | <b>ID-004</b>                                                                                                                                       |
+|-------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------|
+| EPC               | Most identifiers are mainly assigned to objects, but not to logical objects. SSCC can be assigned for shipping containers and SGLN can be assigned only for locations.                  | Registered issuing agencies may issue identifiers and a hierarchical structure of issuing agencies is provided.                                                                                                                                                                                                               | Each identifier is assured to be globally unique.                                                                                                   |
+| ISO/IEC 15459-x   | Identifiers are mainly assigned for objects, but not places. Since this identification scheme is designed for ID tags, it is impossible to assign the identifier to any logical object. | Registered issuing agencies may issue identifiers and a hierarchical structure of issuing agencies is provided.                                                                                                                                                                                                               | Each identifier is assured to be globally unique.                                                                                                   |
+| ISO 6709          | Identifiers are assigned for geographic point locations. This identifier cannot be assigned to any objects that move around.                                                            | It is a representation for identifying geographic point locations, thus no one can issue the identifiers.                                                                                                                                                                                                                     | Each identifier is assured to be globally unique.                                                                                                   |
+| ISBN              | ISBN numbers are assigned only for books and physical publications. ISBN numbers are not assignable for any logical objects and other physical objects.                                 | Only affiliated organizations (sometimes national organizations) that manage books in the region or country may issue the ISBN numbers.                                                                                                                                                                                       | Identifiers are assured to be globally unique.                                                                                                      |
+| ISSN              | ISSN numbers are assigned only for serial publications. ISSN numbers are not assignable for any other logical or physical objects.                                                      | Only affiliated organizations (sometimes national organizations) that manage serial publications in the region or country may issue the ISSN numbers.                                                                                                                                                                         | Identifiers are assured to be globally unique.                                                                                                      |
+| UUID              | Identifiers can be assigned for everything that can be identified.                                                                                                                      | Individual users or programs may issue identifiers. Since central coordination is difficult in this identification scheme, it is not suitable for organizations that want to control issuance of identifiers from the fixed numbering space that can freely be managed by the organization to hierarchically manage products. | Each identifier is almost assured to be globally unique, but there is small possibility of collisions (except if the UUID is registered as an OID). |
+
+**Table I.1 – Analysis of existing identification schemes**
+
+| ID schemes                        | ID-002                                                                                                                                                                                     | ID-003                                                                                                                                                      | ID-004                                            |
+|-----------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------|
+| ISO/IEC 15963                     | Identifiers are mainly assigned for objects, but not places. Since this identification scheme is designed for RFID tags, it is impossible to assign the identifier to any logical objects. | This identifier is always written into RFID tags when a tag chip manufacturer produces an RFID tag. Only tag chip manufacturers can issues this identifier. | Each identifier is assured to be globally unique. |
+| ISO/IEC 11784                     | Identifiers are assigned only for animals.                                                                                                                                                 | Registered issuing agencies may issue identifiers and a hierarchical structure of issuing agencies is provided.                                             | Each identifier is assured to be globally unique. |
+| ITU-T H.642 identification scheme | An ITU-T H.642 identifier can be assigned for multimedia information and services associated with any object or place.                                                                     | Registered issuing agencies may issue identifiers and a hierarchical structure of issuing agencies is provided.                                             | Each identifier is assured to be globally unique. |
+
+#### I.4.3 Summarized analysis
+
+Table I.2 summarizes the information given in the preceding clauses. According to this investigation, it is considered that no existing identification scheme other than the ITU-T H.642 identification scheme satisfies all the requirements described in [ITU-T F.771].
+
+**Table I.2 – Summary of analysis**
+
+|                                                         | ID-002 | ID-003 | ID-004 |
+|---------------------------------------------------------|--------|--------|--------|
+| EPC                                                     | U      | S      | S      |
+| ISO/IEC 15459-x                                         | U      | S      | S      |
+| ISO 6709                                                | U      | U      | S      |
+| ISBN                                                    | U      | S      | S      |
+| ISSN                                                    | U      | S      | S      |
+| UUID                                                    | S      | U      | P      |
+| ISO/IEC 15963                                           | U      | P      | S      |
+| ISO/IEC 11784                                           | U      | S      | S      |
+| ITU-T H.642 identification scheme                       | S      | S      | S      |
+| S: satisfied, U: unsatisfied, P: Not strictly satisfied |        |        |        |
+
+## Bibliography
+
+- [b-ITU-T X.667] Recommendation ITU-T X.667 (2008) | ISO/IEC 9834-8:2008, *Information technology – Open Systems Interconnection – Procedures for the operation of OSI Registration Authorities: Generation and registration of Universally Unique Identifiers (UUIDs) and their use as ASN.1 object identifier components*.
+- [b-ITU-T X.680] Recommendation ITU-T X.680 (2002) | ISO/IEC 8824-1:2002, *Information technology – Abstract Syntax Notation One (ASN.1): Specification of basic notation*.
+- [b-ISO 2108] ISO 2108 (2005), *Information and documentation – International standard book number (ISBN)*.
+- [b-ISO 3297] ISO 3297 (2007), *Information and documentation – International standard serial number (ISSN)*.
+- [b-ISO 6709] ISO 6709 (2008), *Standard representation of geographic point location by coordinates*.
+- [b-ISO 11784] ISO/IEC 11784 (1996), *Radio frequency identification of animals – Code structure*.
+- [b-ISO/IEC 15459-x] ISO/IEC 15459-x, *Information technology – Unique identifiers*.
+- [b-ISO/IEC 15963] ISO/IEC 15963 (2009), *Information technology – Radio frequency identification for item management – Unique identification for RF tags*.
+- [b-uID] uID (2009), *Ubiquitous Code: ucode*, uID center, Version 1.A0.10.
+
+
+
+
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                             |
+|-----------------|---------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                           |
+| Series D        | General tariff principles                                                                   |
+| Series E        | Overall network operation, telephone service, service operation and human factors           |
+| Series F        | Non-telephone telecommunication services                                                    |
+| Series G        | Transmission systems and media, digital systems and networks                                |
+| <b>Series H</b> | <b>Audiovisual and multimedia systems</b>                                                   |
+| Series I        | Integrated services digital network                                                         |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals |
+| Series K        | Protection against interference                                                             |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant     |
+| Series M        | Telecommunication management, including TMN and network maintenance                         |
+| Series N        | Maintenance: international sound programme and television transmission circuits             |
+| Series O        | Specifications of measuring equipment                                                       |
+| Series P        | Terminals and subjective and objective assessment methods                                   |
+| Series Q        | Switching and signalling                                                                    |
+| Series R        | Telegraph transmission                                                                      |
+| Series S        | Telegraph services terminal equipment                                                       |
+| Series T        | Terminals for telematic services                                                            |
+| Series U        | Telegraph switching                                                                         |
+| Series V        | Data communication over the telephone network                                               |
+| Series X        | Data networks, open system communications and security                                      |
+| Series Y        | Global information infrastructure, Internet protocol aspects and next-generation networks   |
+| Series Z        | Languages and general software aspects for telecommunication systems                        |

marked/Y/T-REC-Y.1251-200208-I_PDF-E/raw.md

@@ -0,0 +1,381 @@
+
+
+![ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg)
+
+ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.
+
+INTERNATIONAL TELECOMMUNICATION UNION
+
+**ITU-T**
+
+TELECOMMUNICATION  
+STANDARDIZATION SECTOR  
+OF ITU
+
+**Y.1251**
+
+(08/2002)
+
+SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE  
+AND INTERNET PROTOCOL ASPECTS
+
+Internet protocol aspects – Architecture, access, network  
+capabilities and resource management
+
+# --- **General architectural model for interworking**
+
+ITU-T Recommendation Y.1251
+
+---
+
+## ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE AND INTERNET PROTOCOL ASPECTS
+
+|                                                                           |                      |
+|---------------------------------------------------------------------------|----------------------|
+| GLOBAL INFORMATION INFRASTRUCTURE                                         |                      |
+| General                                                                   | Y.100–Y.199          |
+| Services, applications and middleware                                     | Y.200–Y.299          |
+| Network aspects                                                           | Y.300–Y.399          |
+| Interfaces and protocols                                                  | Y.400–Y.499          |
+| Numbering, addressing and naming                                          | Y.500–Y.599          |
+| Operation, administration and maintenance                                 | Y.600–Y.699          |
+| Security                                                                  | Y.700–Y.799          |
+| Performances                                                              | Y.800–Y.899          |
+| INTERNET PROTOCOL ASPECTS                                                 |                      |
+| General                                                                   | Y.1000–Y.1099        |
+| Services and applications                                                 | Y.1100–Y.1199        |
+| <b>Architecture, access, network capabilities and resource management</b> | <b>Y.1200–Y.1299</b> |
+| Transport                                                                 | Y.1300–Y.1399        |
+| Interworking                                                              | Y.1400–Y.1499        |
+| Quality of service and network performance                                | Y.1500–Y.1599        |
+| Signalling                                                                | Y.1600–Y.1699        |
+| Operation, administration and maintenance                                 | Y.1700–Y.1799        |
+| Charging                                                                  | Y.1800–Y.1899        |
+
+*For further details, please refer to the list of ITU-T Recommendations.*
+
+# **ITU-T Recommendation Y.1251**
+
+# **General architectural model for interworking**
+
+## **Summary**
+
+This Recommendation specifies a general architectural model for interworking that can be used to analyze, categorize and describe cases of interworking between networks.
+
+Two interworking methods are identified, namely **Service Interworking** and **Network Interworking**.
+
+## **Source**
+
+ITU-T Recommendation Y.1251 was prepared by ITU-T Study Group 13 (2001-2004) and approved under the WTSA Resolution 1 procedure on 13 August 2002.
+
+## **Keywords**
+
+Interworking, Network Interworking, Service Interworking.
+
+## FOREWORD
+
+The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
+
+The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
+
+The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
+
+In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC.
+
+## NOTE
+
+In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
+
+## INTELLECTUAL PROPERTY RIGHTS
+
+ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process.
+
+As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database.
+
+© ITU 2002
+
+All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU.
+
+## CONTENTS
+
+|                                                                                  | <b>Page</b> |
+|----------------------------------------------------------------------------------|-------------|
+| 1 Scope .....                                                                    | 1           |
+| 2 References.....                                                                | 1           |
+| 3 Definitions .....                                                              | 1           |
+| 4 Abbreviations.....                                                             | 2           |
+| 5 Interworking – General considerations.....                                     | 2           |
+| 5.1 The problem space.....                                                       | 2           |
+| 5.2 Possible solutions .....                                                     | 2           |
+| 6 Protocol adjacency relationships .....                                         | 4           |
+| 6.1 Layering principle .....                                                     | 4           |
+| 6.2 Peering principle.....                                                       | 5           |
+| 7 Generic interworking model.....                                                | 5           |
+| 8 Application of the model to service interworking and network interworking..... | 6           |
+| 8.1 Service interworking .....                                                   | 6           |
+| 8.2 Network interworking .....                                                   | 7           |
+| 9 Related principles .....                                                       | 9           |
+
+
+
+# ITU-T Recommendation Y.1251
+
+# General architectural model for interworking
+
+# 1 Scope
+
+This Recommendation specifies a generic interworking model that can be used to analyze, categorize and describe cases of interworking between networks.
+
+## 2 References
+
+The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation.
+
+- [1] ITU-T Recommendation I.510 (1993), *Definitions and general principles for ISDN interworking*.
+- [2] ITU-T Recommendation G.805 (2000), *Generic functional architecture of transport networks*.
+- [3] ITU-T Recommendation Y.1001 (2000), *IP framework – A framework for convergence of telecommunications network and IP network technologies*.
+- [4] ITU-T Recommendation Y.1401 (2000), *General requirements for interworking with Internet Protocol (IP)-based networks*.
+
+## 3 Definitions
+
+For the purposes of this Recommendation the following definitions are employed. Consistency with definitions in other Recommendations has been taken into account and is noted where appropriate.
+
+**3.1 interworking:** The term interworking is used to express interactions between networks, between end systems, or between parts thereof, with the aim of providing a functional entity capable of supporting an end-to-end communication. The interactions required to provide a functional entity rely on functions and on the means to select these functions.
+
+NOTE – This definition is identical to that given in ITU-T Rec. I.510, see [1].
+
+**3.2 service interworking:** In service interworking, the Interworking Function (IWF) of Figure 4 terminates the protocol used in network 1 and translates (i.e., mapping) the Protocol Control Information (PCI) to the PCI of the protocol used in network 2 for User, Control and Management Plane functions to the extent possible. In general, since not all functions may be supported in one or other of the networks, the translation of PCI may be partial or non-existent. However, this should not result in any loss of user data since the payload is not affected by PCI conversion at the service interworking IWF.
+
+NOTE – This definition is identical to that given in ITU-T Rec. Y.1401, see [4].
+
+**3.3 network interworking:** In network interworking, the PCI of the protocol used in network 1 and network 2 and the payload information are transferred transparently by an IWF of Figure 4. Typically the IWF encapsulates (known as tunnelling in some specifications) the information which is transmitted by means of an adaptation function and transfers it transparently to the other network.
+
+NOTE – This definition is identical to that given in ITU-T Rec. Y.1401, see [4].
+
+**3.4 adaptation function:** A processing function which adapts the client layer network characteristic information into a form suitable for transport over a trail<sup>1</sup> in the server layer network.
+
+NOTE – This definition is taken from ITU-T Rec. G.805, see [2].
+
+## 4 Abbreviations
+
+This Recommendation uses the following abbreviations:
+
+IP      Internet Protocol  
+IWF    Interworking Function  
+IWU    Interworking Unit  
+PCI    Protocol Control Information
+
+## 5 Interworking – General considerations
+
+### 5.1 The problem space
+
+The objective of interworking is to provide end-to-end connectivity across two separate networks, N1 and N2, which cannot be directly interconnected due to the deployment of different protocols in each of these networks.
+
+Simply, the problem to be solved is illustrated in Figure 1.
+
+![Diagram illustrating the interworking problem between Network 1 and Network 2.](731f533b0599c8e42a063f06e4332045_img.jpg)
+
+The diagram shows two ovals representing 'Network 1' and 'Network 2'. Above them is a double-headed horizontal arrow with a question mark '?' in the center. Below the ovals, the text 'N1 stack not equal N2 stack' is written. The identifier 'Y.1251\_F01' is located at the bottom right of the diagram.
+
+Diagram illustrating the interworking problem between Network 1 and Network 2.
+
+**Figure 1/Y.1251 – The interworking problem**
+
+The lack of direct interconnectivity will arise when the protocol stacks in Network 1 (N1) are different from those in Network 2 (N2), and thus where one, or more protocol discontinuity will occur in an interworking path created to span both N1 and N2. This discontinuity may occur within a single given layer, some set of given layers, or within all layers between the respective networks.
+
+### 5.2 Possible solutions
+
+Two solutions are possible to achieve end-to-end connectivity.
+
+One is to effect a semantically equivalent translation between Network 1 (N1) and Network 2 (N2). The semantic equivalence can be achieved by mapping equivalent service characteristics from N1 to N2. The basic concept is shown in Figure 2, below.
+
+---
+
+<sup>1</sup> See ITU-T Rec. G.805, for further definitions of trail, etc. In this Recommendation, the use of the term "layer" or "protocol layer" is synonymous with the use of the term "layer network" in ITU-T Rec. G.805.
+
+![Diagram showing two separate ovals labeled 'Network 1' and 'Network 2' connected by a double-headed arrow. Below the arrow is the text 'Mapping of service characteristics'. The label 'Y.1251_F02' is at the bottom right.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg)
+
+Mapping of  
+service characteristics
+
+Y.1251\_F02
+
+Diagram showing two separate ovals labeled 'Network 1' and 'Network 2' connected by a double-headed arrow. Below the arrow is the text 'Mapping of service characteristics'. The label 'Y.1251\_F02' is at the bottom right.
+
+**Figure 2/Y.1251 – Interworking by service mapping/translation between N1 and N2**
+
+This solution is only possible if there is sufficient similarity in service characteristics between N1 and N2. In this solution, there is a distinct discontinuity between the protocol layer(s) of N1 and N2. Thus, there is a protocol discontinuity between the user of network N1 and users of network N2. Some services of N1 may not be available to users of N2 and vice versa, due to lack of exact equivalence between all the services of N1 and all the services of N2.
+
+This solution is known as **Service Interworking**.
+
+The other way to achieve end-to-end connectivity is to superimpose one network on top of the other. This can be achieved by encapsulating, via an adaptation function, the relevant protocol(s), one or more, of one network on top of the protocols of the other. This is shown simplistically in Figure 3 for providing the users of N2 with access to N1. In this solution the users of N2 have to deal with the protocol layer(s) of both N2 and N1 (to some or all extent depending on the exact interworking arrangements), when intercommunication between users of N2 and N1 is required.
+
+![Diagram showing two overlapping ovals. The larger oval on the left is labeled 'Network 1'. The smaller oval on the right is labeled 'Network 2' and overlaps with the right side of 'Network 1'. The label 'Y.1251_F03' is at the bottom right.](367926125450c2bc3f4bdca9d59a62ba_img.jpg)
+
+Y.1251\_F03
+
+Diagram showing two overlapping ovals. The larger oval on the left is labeled 'Network 1'. The smaller oval on the right is labeled 'Network 2' and overlaps with the right side of 'Network 1'. The label 'Y.1251\_F03' is at the bottom right.
+
+**Figure 3/Y.1251 – Interworking by superimposition (Encapsulation)**
+
+This second method encapsulates the protocol(s) of N1 within the uppermost protocol of N2. Users of N2, wishing to communicate with users of N1 must use the new stack comprising the N2 stack plus the additional elements of the N1 stack used for the interworking. Theoretically, this new stack may be regarded as a new logical network N3, since users of N2 still communicate amongst themselves using the original N2 stack.
+
+This solution is known as **Network Interworking**. It may also sometimes be called interworking by encapsulation.
+
+In this case there is no protocol discontinuity between users of N1 and users of N2 at the superimposed interworking layer(s).
+
+Equally possible, but not shown in the figure, protocols of N2 could be superimposed over N1.
+
+The functions for interworking between N1 and N2, for either **service interworking** or **network interworking**, are provided by an interworking function (IWF) considered to notionally exist between the N1 and N2, as shown in Figure 4. The exact physical location of the interworking unit (IWU) containing the IWF is an implementation issue, but could be contained within N1, N2, or as an independent unit.
+
+![Figure 4/Y.1251 – Interworking function. This diagram illustrates the interworking function between two networks, Network 1 and Network 2. Network 1 contains Protocol stack 1, which is divided into three horizontal layers: Management plane, Control plane, and User plane. Network 2 contains Protocol stack 2, also divided into Management plane, Control plane, and User plane. Between the two networks is an Interworking Function (IWF). Double-headed arrows indicate bidirectional communication between the Management planes, Control planes, and User planes of the two stacks, as well as between each stack and the IWF. The label 'Y.1251_F04' is located in the bottom right corner.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg)
+
+Figure 4/Y.1251 – Interworking function. This diagram illustrates the interworking function between two networks, Network 1 and Network 2. Network 1 contains Protocol stack 1, which is divided into three horizontal layers: Management plane, Control plane, and User plane. Network 2 contains Protocol stack 2, also divided into Management plane, Control plane, and User plane. Between the two networks is an Interworking Function (IWF). Double-headed arrows indicate bidirectional communication between the Management planes, Control planes, and User planes of the two stacks, as well as between each stack and the IWF. The label 'Y.1251\_F04' is located in the bottom right corner.
+
+**Figure 4/Y.1251 – Interworking function**
+
+## 6 Protocol adjacency relationships
+
+The two methods of interworking described in clause 5 result in the need to position protocols in two different ways. The service interworking method results in the establishment of a horizontal positioning relationship between the protocols of N1 and N2. The network interworking method results in a vertical positioning relationship between the protocols of N1 and N2.
+
+These basic positioning relationships are shown in Figure 5.
+
+Two basic principles are involved, namely a vertical layering principle and a horizontal peering principle. Note, these principles are identical to those described in ITU-T Rec. Y.1001, see [3].
+
+![Figure 5/Y.1251 – Protocol adjacency relationships. This diagram shows the relationships between three protocols: Protocol A, Protocol B, and Protocol X. Protocol A and Protocol B are enclosed in a dashed box, indicating a layering relationship where Protocol A is encapsulated within Protocol B. A thick double-headed vertical arrow between them is labeled 'Layering relationship'. Protocol A and Protocol X are shown outside this box, with a thick double-headed horizontal arrow between them labeled 'Peering relationship'. Arrows labeled 'Service mapping & adaptation' point from Protocol A to Protocol B and from Protocol X to Protocol A. An arrow labeled 'Service mapping & protocol translation' points from Protocol X to Protocol A. The label 'Y.1251_F05' is in the bottom right corner.](053f1077d592e6622cd21dc4bb4cb366_img.jpg)
+
+Figure 5/Y.1251 – Protocol adjacency relationships. This diagram shows the relationships between three protocols: Protocol A, Protocol B, and Protocol X. Protocol A and Protocol B are enclosed in a dashed box, indicating a layering relationship where Protocol A is encapsulated within Protocol B. A thick double-headed vertical arrow between them is labeled 'Layering relationship'. Protocol A and Protocol X are shown outside this box, with a thick double-headed horizontal arrow between them labeled 'Peering relationship'. Arrows labeled 'Service mapping & adaptation' point from Protocol A to Protocol B and from Protocol X to Protocol A. An arrow labeled 'Service mapping & protocol translation' points from Protocol X to Protocol A. The label 'Y.1251\_F05' is in the bottom right corner.
+
+**Figure 5/Y.1251 – Protocol adjacency relationships**
+
+### 6.1 Layering principle
+
+In this case, there is a vertical relationship between Protocol A and Protocol B. This is a layering relationship.
+
+Protocol A is encapsulated within Protocol B, and uses the layer service offered by Protocol B. In general, no fixed relationship between the actual protocols playing in the role of Protocol A or Protocol B can be assumed. In general, protocols can be combined in arbitrary ways. For, example,
+
+Frame Relay can be operated over IP, or IP may be operated over Frame Relay according to the circumstances pertaining.
+
+As far as the adaptation is concerned, an adaptation protocol may or may not involve additional protocol control information (PCI) of a shim layer format, depending on the type of mapping required. In some cases, the adaptation may simply be a question of a mapping procedure with no additional PCI being required. In other cases, additional PCI may be required to effect the encapsulation process.
+
+### 6.2 Peering principle
+
+In this case, an end-to-end service is being provided by performing a translation and conversion function between Protocol A and Protocol X, via some form of IWF interposed between Protocol A and Protocol X. The IWF terminates each protocol (Protocol A and Protocol X) and performs a mapping between the services offered by Protocol A and Protocol X.
+
+## 7 Generic interworking model
+
+The cases described above apply in general to a variety of complex protocol arrangements. Generally, all these cases can be specified in terms of horizontal and/or vertical relationships between adjacent protocols. In this regard, for modelling purposes, it is only necessary to consider two adjacent horizontal protocols and two vertical protocols as shown in Figure 6. All cases, can be fully described by such a model either by degeneration for the case of single layer, or recursive application of the model to the other adjacencies that would exist in a multi-layer situation. This principle applies to the user, control and management planes.
+
+![Figure 6/Y.1251 – Generic interworking model diagram](5e92d9e8e9ce204e405bff2367f88176_img.jpg)
+
+The diagram illustrates the Generic interworking model. It consists of four rectangular boxes arranged in a 2x2 grid. The top-left box is labeled 'Protocol A', the top-right box is labeled 'Protocol X', the bottom-left box is labeled 'Protocol B', and the bottom-right box is labeled 'Protocol Y'. Between the top row and bottom row, there are two vertical double-headed arrows. The left arrow is labeled 'A/B Adaptation functions' and the right arrow is labeled 'X/Y Adaptation functions'. Between the left column and right column, there are two horizontal double-headed arrows, both labeled 'Translation functions'. The diagram shows the relationships between protocols in both horizontal and vertical dimensions.
+
+Y.1251\_F06
+
+Figure 6/Y.1251 – Generic interworking model diagram
+
+**Figure 6/Y.1251 – Generic interworking model**
+
+Every interworking arrangement can now be described by comparing the horizontal protocol adjacencies, A-X and B-Y, and vertical adjacencies A-B and X-Y. The model can be re-applied to all pairwise adjacencies, to analyze the entire relationship and possible solutions for between any two disparate protocol stacks belonging to different networks.
+
+For example, if protocol A is not equal to protocol X, but sufficient semantic equivalence exists, protocol A could be translated to X by a semantic functional mapping elements of the interworking functions contained in an interworking unit. This case also embraces the concept service interworking case, where end-to-end semantics across the IWF are preserved by service mapping.
+
+Alternatively, if this is not possible or desirable, then a common protocol, say protocol A, must be used on both sides (i.e., protocol X becomes the same as protocol A) and is encapsulated within protocol Y by some interworking adaptation function. This is the case of superimposing N1 over N2, interworking by encapsulation. An adaptation protocol may or may not involve additional protocol control information (PCI) of a shim layer format, depending on the type of mapping required. This embraces the concept of network interworking.
+
+It should be noted that in this Recommendation the use of the term peer-to-peer will not be associated with any given protocol, for the following reasons:
+
+- a) All protocols that generate formats (i.e., specific and explicit syntax) are peer-to-peer, in that there is always source for generating the protocol format and sink for receiving the protocol in a given stratum of operation (in the same layer or sub-layer). This fact says nothing about the specific role of any specific protocol itself, i.e., what it is being used for, or anything about its type.
+- b) Some interworking adaptation protocols do not generate any format (syntax) as such. This is true of many interworking protocols which provide mapping functions from one layer to a lower layer. These are still be peer-to-peer, i.e., implicitly operating between corresponding remote peer entities. For example, Fragmentation and Reassembly procedures fall into this category, in that they have defined procedures but generate no format for transmission and/or reception.
+- c) It is not possible to label a protocol as being of a particular absolute kind. Any given protocol can play many different roles in different contexts. There are numerous examples, where protocols may play different roles in different contexts.
+
+## **8 Application of the model to service interworking and network interworking**
+
+The following two clauses show application of the generic model to the Service Interworking and Network Interworking cases.
+
+### **8.1 Service interworking**
+
+Figure 7 shows an example of service interworking by service mapping. In this example, there is a protocol discontinuity at the interworking layer, since protocol A and protocol X are not identical. Mapping and translation functions are used to convert the services provided by protocol A into formats and services provided by protocol X.
+
+![Diagram illustrating the application of a model to service interworking between four protocols: Protocol A, Protocol X, Protocol B, and Protocol Y.](af7916c89a458fdab6c3f443217388ae_img.jpg)
+
+The diagram illustrates the application of a model to service interworking between four protocols: Protocol A, Protocol X, Protocol B, and Protocol Y. The protocols are arranged in a 2x2 grid. Protocol A is at the top-left, Protocol X at the top-right, Protocol B at the bottom-left, and Protocol Y at the bottom-right. The connections between the protocols are as follows:
+
+- Protocol A and Protocol X:** Connected by a horizontal double-headed arrow labeled "Interworking translation functions". Below this arrow, the text "A not equal X" is present.
+- Protocol A and Protocol B:** Connected by a vertical double-headed arrow labeled "A/B Adaptation functions".
+- Protocol X and Protocol Y:** Connected by a vertical double-headed arrow labeled "X/Y Adaptation functions".
+- Protocol B and Protocol Y:** Connected by a horizontal double-headed arrow labeled "Interworking translation functions". Above this arrow, the text "B equal Y, or B not equal Y" is present.
+
+The diagram is labeled "Y.1251\_F07" in the bottom right corner.
+
+Diagram illustrating the application of a model to service interworking between four protocols: Protocol A, Protocol X, Protocol B, and Protocol Y.
+
+**Figure 7/Y.1251 – Application of model to service interworking**
+
+### 8.2 Network interworking
+
+Figure 8 shows the case where the protocol of N1 is superimposed over the protocol of N2 to effect interworking. In this case, protocol A is transferred across the IWF to become protocol X. Thus it is, in fact, protocol A, which now has to be encapsulated over protocol Y, via some suitable adaptation function and may be an additional adaptation shim layer protocol. In this case, there are protocol discontinuities at layers B and Y, but no protocol discontinuity at the upper layer since protocol X is identical to protocol A, i.e., there is a single common protocol across N1 and N2 (for interworking purposes).
+
+![Figure 8/Y.1251: Application of model to Network Interworking. This diagram illustrates a network interworking model. At the top, 'Protocol A' and 'Protocol X' are connected by a bidirectional arrow, with a box labeled 'A equal X' between them. Below this, 'Protocol B' and 'Protocol Y' are connected by a bidirectional arrow, with a box labeled 'B not equal Y' between them. In the center, 'Interworking translation functions' are shown. On the left, 'A/B Adaptation functions' connect 'Protocol A' and 'Protocol B'. On the right, 'X/Y Adaptation functions' connect 'Protocol X' and 'Protocol Y'. The diagram is labeled 'Y.1251_F08' at the bottom right.](4801720824e4b5e2361a5564f91cfb70_img.jpg)
+
+Figure 8/Y.1251: Application of model to Network Interworking. This diagram illustrates a network interworking model. At the top, 'Protocol A' and 'Protocol X' are connected by a bidirectional arrow, with a box labeled 'A equal X' between them. Below this, 'Protocol B' and 'Protocol Y' are connected by a bidirectional arrow, with a box labeled 'B not equal Y' between them. In the center, 'Interworking translation functions' are shown. On the left, 'A/B Adaptation functions' connect 'Protocol A' and 'Protocol B'. On the right, 'X/Y Adaptation functions' connect 'Protocol X' and 'Protocol Y'. The diagram is labeled 'Y.1251\_F08' at the bottom right.
+
+**Figure 8/Y.1251 –Application of model to Network Interworking**
+
+A common usage/application of this method involves three physically separate networks, where two similar networks N1 and N3 are interconnected via a third dissimilar network N2, as shown in Figure 9.
+
+![Figure 9/Y.1251: Example of Network Interworking. This diagram shows three networks: N1, N2, and N3. N1 and N3 are connected to N2 via two 'IWU' (Interworking Units). N1 contains 'Protocol A' and 'Protocol B'. N2 contains 'Protocol X (X := A)' and 'Protocol Y'. N3 contains 'Protocol A' and 'Protocol B'. Bidirectional arrows connect 'Protocol A' in N1 to 'Protocol X' in N2, and 'Protocol A' in N3 to 'Protocol X' in N2. Bidirectional arrows connect 'Protocol B' in N1 to 'Protocol Y' in N2, and 'Protocol B' in N3 to 'Protocol Y' in N2. The diagram is labeled 'Y.1251_F09' at the bottom right.](a33da0f14e456f92539ce3e9b7d81f9a_img.jpg)
+
+Figure 9/Y.1251: Example of Network Interworking. This diagram shows three networks: N1, N2, and N3. N1 and N3 are connected to N2 via two 'IWU' (Interworking Units). N1 contains 'Protocol A' and 'Protocol B'. N2 contains 'Protocol X (X := A)' and 'Protocol Y'. N3 contains 'Protocol A' and 'Protocol B'. Bidirectional arrows connect 'Protocol A' in N1 to 'Protocol X' in N2, and 'Protocol A' in N3 to 'Protocol X' in N2. Bidirectional arrows connect 'Protocol B' in N1 to 'Protocol Y' in N2, and 'Protocol B' in N3 to 'Protocol Y' in N2. The diagram is labeled 'Y.1251\_F09' at the bottom right.
+
+**Figure 9/Y.1251 – Example of Network Interworking**
+
+In such a case we have application of two IWUs. Both the IWFs apply adaptation functions, i.e., encapsulation and decapsulation at the border between N1 and N2 and at the border between N2 and N3 for the bidirectional carriage of the common N1/N3 protocol over N2. In this case, the protocol of N1/N3 is carried transparently over N2. When only two dissimilar networks are involved one of the end systems could be regarded as constituting a third network handling the common protocol.
+
+## 9 Related principles
+
+In general, it can be stated that whenever any protocol stack difference exists between two networks, interworking is required to interconnect the two networks. This general principle is independent of the method used to achieve such interworking, i.e., irrespective of whether the service interworking method of 8.1 or the network interworking of 8.2 is used to effect such interworking.
+
+Any protocol discontinuity between N1 and N2, at any layer of their respective stacks, constitutes interworking. For example, if N1 were IP over a Local Area Network and N2 was IP over Frame Relay, interworking is taking place between the Local area Network and the Frame Relay network because of the layer 2 discontinuity, even though there is no discontinuity at layer 3 (the IP layer). Adaptation functions are required for IP over the LAN layer 2 protocol and for IP over the Frame Relay protocol.
+
+If layer N is the uppermost layer from the interworking standpoint, there must be at least one layer protocol discontinuity between the protocol stacks of networks N1 and N2 for their interconnection to be considered as an interworking case. This discontinuity may occur at layer N itself, or at any other layer N-j (for j less than N; j greater equal 1), or at several layers simultaneously including or excluding the layer N itself. It should also be noted that the number of layer protocols in each stack may be different.
+
+In general, mappings between features may span several layers. It cannot be assumed that mappings performed purely at a peer level are sufficient, or that each peer layer is independent of the underlying layer(s). For example, a particular feature at layer N in N1 may be required to be mapped to non-peer layer in N2. These considerations may apply particularly to QoS related features and/or aspects.
+
+
+
+
+
+## SERIES OF ITU-T RECOMMENDATIONS
+
+|                 |                                                                                                                                |
+|-----------------|--------------------------------------------------------------------------------------------------------------------------------|
+| Series A        | Organization of the work of ITU-T                                                                                              |
+| Series B        | Means of expression: definitions, symbols, classification                                                                      |
+| Series C        | General telecommunication statistics                                                                                           |
+| Series D        | General tariff principles                                                                                                      |
+| Series E        | Overall network operation, telephone service, service operation and human factors                                              |
+| Series F        | Non-telephone telecommunication services                                                                                       |
+| Series G        | Transmission systems and media, digital systems and networks                                                                   |
+| Series H        | Audiovisual and multimedia systems                                                                                             |
+| Series I        | Integrated services digital network                                                                                            |
+| Series J        | Cable networks and transmission of television, sound programme and other multimedia signals                                    |
+| Series K        | Protection against interference                                                                                                |
+| Series L        | Construction, installation and protection of cables and other elements of outside plant                                        |
+| Series M        | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits |
+| Series N        | Maintenance: international sound programme and television transmission circuits                                                |
+| Series O        | Specifications of measuring equipment                                                                                          |
+| Series P        | Telephone transmission quality, telephone installations, local line networks                                                   |
+| Series Q        | Switching and signalling                                                                                                       |
+| Series R        | Telegraph transmission                                                                                                         |
+| Series S        | Telegraph services terminal equipment                                                                                          |
+| Series T        | Terminals for telematic services                                                                                               |
+| Series U        | Telegraph switching                                                                                                            |
+| Series V        | Data communication over the telephone network                                                                                  |
+| Series X        | Data networks and open system communications                                                                                   |
+| <b>Series Y</b> | <b>Global information infrastructure and Internet protocol aspects</b>                                                         |
+| Series Z        | Languages and general software aspects for telecommunication systems                                                           |
+
+![Barcode graphic with the number * 2 2 8 0 6 * printed below it.](97fe9069356cc2a84e8e70673e405958_img.jpg)
+
+A standard 1D barcode is located in the bottom right corner of the page. Below the vertical bars of the barcode, the alphanumeric string '\* 2 2 8 0 6 \*' is printed.
+
+Barcode graphic with the number \* 2 2 8 0 6 \* printed below it.