视听电信业务中的64至1920 kbit/s信道的帧结构 |
ITU-T H.221建议书旨在定义单个或多个B或H0频道,或者单个H11或H12频道、最佳利用音频和视频编码算法特性和属性、传输帧架构和现行建议书的音视频电信业务的帧架构。它提供了几个优势:- 它考虑了ITU-T G.704、ITU-T X.30/I.461等建议书。它可以允许使用现有的硬件或软件。- 它简单、经济和灵活。可在单微处理器上采用熟悉的硬件原则予以实施。- 它是一个同步过程。配置变化的确切时间与发射机和接收机的时间相同。配置可每隔20毫秒进行变更。- 它不需要用于音视频信号传输的反向链路,因为配置由反复发射的密语发出信号。- 它在出现传输错误时非常安全,因为控制复用的代码由双重纠错码保护。- 它允许同步多个64 kbit/s 或384 kbit/s 连接以及视频会议等多媒体业务情况下同步多连接内架构内音频、视频、数据和其他信号的复用。- 它可用于未通过其他方式提供八位组同步的网络中获得八位组同步。- 它可用于无需对话来协商数据信道使用的多点配置中。- 它向用户提供了各种数据速率(从300 bit/s直至几乎2 Mbit/s)。本建议书的该次修订引入了多项对原版本的改进和澄清,主要是在ITU-T H.320系统中使用ITU-T G.719建议书和G.722.1建议书(14 kHz音频)附件C的描述。 |
|
Citation: |
https://handle.itu.int/11.1002/1000/9690 |
Series title: |
H series: Audiovisual and multimedia systems H.200-H.499: Infrastructure of audiovisual services H.220-H.229: Transmission multiplexing and synchronization |
Approval date: |
2009-03-16 |
Approval process: | AAP |
Status: |
In force |
Maintenance responsibility: |
ITU-T Study Group 16 |
Further details: |
Patent statement(s)
Development history
|
|
|
|
ITU-T Supplement
|
Title
|
Status
|
Summary
|
Table of contents
|
Download
|
H Suppl. 6 (04/2006)
|
Control load quantum for decomposed gateways
|
In force
|
here
|
here
|
here
|
H Suppl. 9 (05/2008)
|
Gateway control protocol: Operation of H.248 with H.225.0, SIP, and ISUP in support of emergency telecommunications service (ETS)/international emergency preference scheme (IEPS)
|
In force
|
here
|
here
|
here
|
H Suppl. 11 (02/2009)
|
Analysis of class-based home network QoS solutions
|
In force
|
here
|
here
|
here
|
H Suppl. 12 (11/2013)
|
Gateway control protocol: Priority traffic treatment by ITU-T H.248 gateways
|
In force
|
here
|
here
|
here
|
H Suppl. 13 (10/2015)
|
Gateway control protocol: Common ITU-T H.248 terminology - Release 2
|
In force
|
here
|
here
|
here
|
H Suppl. 14 (10/2015)
|
Gateway control protocol: SDP codepoints for gateway control - Release 2
|
In force
|
here
|
here
|
here
|
H Suppl. 15 (01/2017)
|
Conversion and coding practices for HDR/WCG Y'CbCr 4:2:0 video with PQ transfer characteristics
|
In force
|
here
|
here
|
here
|
H Suppl. 17 (11/2014)
|
Guide for addressing accessibility in standards
|
In force
|
here
|
here
|
here
|
H Suppl. 18 (10/2017)
|
Signalling, backward compatibility and display adaptation for HDR/WCG video coding
|
In force
|
here
|
here
|
here
|
H Suppl. 19 (04/2021)
|
Usage of video signal type code points
|
In force
|
here
|
here
|
here
|
Title |
Approved on |
Download |
Testing of personal audio systems for compliance with ITU-T H.870 (2018)
|
2024
|
|
Testing of personal audio systems for compliance with ITU-T H.870 (2018)
|
2021
|
here
|
Telecommunications Accessibility Checklist
|
2006
|
here
|
|