GB/T 38828-2020Technical requirements for IPTV media delivery system—Use cases and requirements (English PDF)

3.1 Terms and definitions

The following terms and definitions apply to this document.

3.1.1 Time-shift television

Perform short pause, rewind and fast forward operations on the broadcast and TV content channels played in real time.

3.1.2 Electronic program guide

The list of digital TV programs combined according to different classification rules is provided to users electronically.

Note: The user can view it through the remote control, or directly switch from the electronic program list to the program being played.

3.1.3 Push

According to the requirements of the service provider, the media content is packaged and delivered to the system intermediate node or the service or operation of multiple terminal users.

3.1.4 Service provider

Operators that provide telecommunications services to consumers and other clients in accordance with price lists or contracts.

Note: The service provider may or may not operate the network, and may or may not be a customer of another service provider.

3.1.5 Delivery

Send content to end users.

3.1.6 Distribution

Send the content to the appropriate intermediate location for subsequent delivery.

3.2 Abbreviations

The following abbreviations apply to this document. ARQ. Automatic Repeat Request (AutomaticRepeatRequest)

EPG. Electronic Program Guide (ElectronicProgramGuide)

FCC. Fast Channel Change Service (FastChannelChange)

FEC. Forward error correction (Forwarderrorcorrection)

IP. Internet Protocol (InternetProtocol)

IPTV. Internet Protocol Television (InternetProtocolTelevision)

QoE. Quality of Experience (Quality of Experience)

QoS. Quality of Service (Quality of Service)

5.1 IPTV media distribution and delivery application scenarios

5.2 Capability or resource service application scenarios

5.2.1 Application scenarios of data processing services

With the continuous development of data processing technology and the data processing capabilities of equipment, the content used by users is usually in a variety of encoding formats, graphics The film format and file format exist. When using different facilities to use these contents, due to the decoding capabilities and display capabilities of the corresponding equipment The content format of the service to be provided needs to be converted. When there is a large amount of content that needs to be formatted, the conversion frequency is similar.

For smaller cases, if the IPTV content provider itself performs the corresponding work, it needs to spend a lot of money to purchase the corresponding equipment to Completion makes the cost of corresponding data processing higher. If the data processing capability of the IPTV media delivery system is used as content The owner or content provider completes the above-mentioned format conversion and other tasks, which can save users the cost of purchasing the corresponding equipment. In this application scenario, The IPTV media delivery system uses its own redundant data processing capabilities to provide users with corresponding data processing services.

This application scenario includes but is not limited to audio and video content transcoding services, image format conversion services, content hot update services, and small files Aggregation services, etc.

5.2.2 Application Scenarios of Statistics Service

IPTV content providers need to understand the usage of their various resources. For example, within a certain period of time, the content they provide is accessed by users.

Ask the overall situation, access to specific content and statistical information such as the area covered by users accessing its content. Should be In the application scenario, the IPTV media delivery system uses the user information collected when the user accesses the content information provided by the corresponding content provider.

Log information such as the accessed content and the address information of the accessing user, according to the specific needs of the IPTV content provider, after the collected Perform statistical analysis on the data, and report the statistical analysis results to content providers to provide statistical services; at the same time, the IPTV media delivery system also The experience accumulated in the past and the user's access to the content provided by the corresponding content provider can be used to analyze and determine the Corresponding security threats that may be brought by content sources, provide content providers with corresponding report information.

This application scenario includes but is not limited to user usage statistics services.

5.2.3 QoE Improved Service Application Scenarios

The improvement of user experience quality involves all links in the entire chain from content source to user terminal, corresponding to different application methods QoE indicators are also different. For live broadcast services, the switching speed of channels is also one of the indicators that affect the quality of user experience.

The difference in packet and network congestion levels are also related factors that affect the quality of user experience. Some of the above factors can usually be found in the ring closest to the user end.

Section adopts corresponding technology or strategy to solve, thereby improving the quality of user experience. In this application scenario, the IPTV media delivery system provides Providers can use their own technology to provide content providers with corresponding services that improve the quality of user experience.

This application scenario includes but is not limited to ARQ, FCC, code stream adaptive service, packet loss compensation service, and FEC service.

6.1 Requirements of service providers for media delivery systems

The requirements of business providers for media delivery systems are as follows.

a) Support distributed media delivery system architecture;

b) Support services provided by means of recording and broadcasting live broadcast, live live broadcast, on-demand, download, push, network personal recording or live broadcast time shift And application and virtual content delivery system services;

c) Support information insertion or information services (including emergency notification or broadcast) with regional characteristics or personalized information;

d) Support the simultaneous provision of the same business or service to end users who adopt different access methods and different types of terminals;

e) When using the on-demand method to provide services, support the interactive control of the end user on the media content consumed (for example, using 2, 4, 8 Controls such as fast forward and fast reverse at equal multiples);

f) When providing live broadcast services, support end users to review the content of live broadcasts that have been broadcast for a period of time;

g) Support end users to use the media delivery system to record the selected content according to their personal needs;

h) Support transparent transmission of media content;

i) Support the distributed storage or caching of specified media content according to the requirements of the service provider, and support the update of the media content (including Including additions and deletions).

6.2 End user needs for media delivery system

The end users' requirements for the media delivery system are as follows.

a) Support end users to use business or services with different types of terminals (including smart phones, TVs with set-top boxes, and computers)

At the same time, it supports that during the use of the business, the end user can replace the end user terminal according to their own needs without interrupting the terminal User use business;

b) Provide acceptable business service quality requirements, and the service quality provided by the system should meet the requirements of 11.1 and YD/T 1823-2008

YD/T 1654-2007 in 7.3.2 regulations;

c) Support the upload and delivery services of end-user media content (e.g. end-user email and other media information, optional);

d) Support to reserve storage space for end users to store relevant media content according to the request of end users;

e) Support the distribution and delivery of personalized media content and advertising content.

6.3 Requirements for media delivery system functions

The requirements for the functions of the media delivery system are as follows.

a) Support distributed media content storage or caching;

b) Support distributed businesses and services;

c) Support on-demand, live broadcast (recorded live broadcast, live broadcast), download, push, time-shifted TV, network recording, broadcast control and other services and service;

d) Support unicast and multicast transmission methods;

e) Support load balancing;

f) Ensure the reliability and security of business and content;

g) Provide support for multi-service operators;

h) Have the ability to guarantee QoS and QoE of the business;

i) Support transparent transmission of content;

j) Provide smooth system expansion capability;

k) Support terminal user authority control and cost control;

l) Support error correction capability for media content distribution;

m) Support the error correction capability of media content storage;

n) Possess error correction and fault tolerance capabilities for streaming services;

o) Support the establishment of virtual media delivery systems and the provision of services;

p) Support the distribution and delivery of distributed media content source content;

q) It has the function of connecting with the IP bearer network;

r) Support media content delivery triggered by two methods. "push" and "pull" (push and request to send);

s) Support media routing function.

6.4 Requirements for information processing functions of media delivery systems

The requirements for the information processing functions of the media delivery system are as follows.

a) The information processing module in the media delivery system should support the preprocessing or real-time processing of media content (encoding, compression, streaming, Slices etc.);

b) In order to support the needs of simultaneously serving different types of terminals, the media delivery system should support the use of different encoding standards to The same information of the provider is processed;

c) Support the transcoding function of media content.

6.5 Demand for media content types provided by media delivery systems

The requirements for the types of media content provided by the media delivery system are as follows.

a) Support single video multi-audio track program stream (for example. one audio with audio description);

b) Support various types of media content (including text, still image, audio, video, multi-audio, multi-text, combined media types Content) distribution and delivery services.

6.6 Requirements for media delivery methods of media delivery systems

The requirements for the media delivery method of the media delivery system are as follows.

a) Support content delivery by push or pull;

b) Support multiple content distribution strategies (such as push according to schedule, dynamic content pull, multi-source content pull);

c) Support media delivery services in unicast or multicast mode according to the strategy;

d) Support the simultaneous delivery of media information from multiple sources to end users with a certain degree of synchronization.

6.7 Demand for media delivery system management

The requirements for media delivery system management are as follows.

a) Support the management of storage media content in the media delivery system;

b) Support the management of the operating status of related equipment in the media delivery system;

c) Support the management of the load status in the media delivery system;

d) Support the management of related information such as the usage of end users who use the media delivery system;

e) Support the management of the usage of service providers using the media delivery system.