1前言电视数字化的主要任务是改变电视的传输方式从而大幅度地提高画质与音质。从目前全国数字电视业务的发展情况来看,各县市分别建立数字电视前端,不仅使节目平台的统一管理实现难度增大,而且基本上是相同节目资源在前端的重复性建设,资金浪费太大,给县市有线网络增加了沉重的负担。而把数字电视平台搭建在地市级,县级网络的节目全部由地级市提供,以县市级分配网为单位推广有线数字电视的整体平 1 Introduction The main task of digital TV is to change the transmission method of television so as to greatly improve the quality and sound quality. Judging from the current development of digital TV business in China, all counties and cities have set up digital TV front-end respectively, which not only makes it more difficult to realize the unified management of program platform, but also is basically the repetitive construction of the same program resources at the front end, Large, to the county cable network has increased a heavy burden. The digital television platform built in the prefecture-level, county-level network programs all provided by the prefecture-level city to county-level distribution network as a unit to promote the overall digital cable flat