ITU-R BT.1126-0(1994-07)文档.pdfVIP

Rec. ITU-R BT.1126 1 RECOMMENDATION ITU-R BT.1126* Data transmission protocols and transmission control scheme for data broadcasting systems using a data channel in satellite television broadcasting (1994) The ITU Radiocommunication Assembly, considering a) that a common transmission protocol should be applied to the data channel of both the digital sub-carrier NTSC system (recommended in Recommendation ITU-R BO.650) and the MUSE system (recommended in Recommendation ITU-R BO.786); b) that various data broadcasting services, such as broadcasting facsimile, telesoftware, digital coded still picture, telemusic etc., are available; c) that multimedia services combined with the above services are also available; d) that flexibility for the various applications is required; e) that expandability is required to expand the several services that appropriate the new technology and the needs of service broadcasters and users; f) that various services can be transmitted efficiently through a data channel with a limited transmission capacity; g) that a flexible conditional access system is desirable to realize several billing systems and several security levels; h) that the desired packets are separated from all the packets of the services broadcast by the several service broadcasters through the data channel with various formats; j) that undesired packets must not operate the receiver; k) that the quality of the data is secured when the received