１概述经过多年的发展，中国的有线电视已经具备相当大的规模。截止目前，国家干线网已连通近３０个省市，全国用户已突破９０００万户。各地网络系统和结构有明显进步。HFC（光纤同轴电缆混合网）成为建网主流，７５０MHz以上的有线电视用户系统已超过４０００万户，具有双向 1 Overview After years of development, China’s cable TV already has a considerable size. Up to now, the national trunk network has been connected to nearly 30 provinces and cities, the national user has exceeded 90 million. The network system and structure all have obvious progress. HFC (optical fiber coaxial cable hybrid network) to become the mainstream network building, more than 750MHz cable television user system has more than 40 million households, with two-way