本世纪70年代的蓬勃发展继本世纪电源线、电话线陆续进入城市居民家庭后，作为声像信号载体的有线电视传输线联结千家万户，给广大用户带来了十分丰富的信息和高质量的视听享受．随着经济与社会的迅速发展和生活节奏的加快，广大观众早已不满足于收看稀少的电视频道播放时幅很 The vigorous development of the 70s of this century, following the power cord of this century, the telephone line after another into the urban households, as the audio and video signal carrier cable television transmission line to connect tens of thousands of households, to bring the vast number of users a very rich information and high quality Audio-visual enjoyment. With the rapid economic and social development and accelerated pace of life, the majority of the audience has long been dissatisfied with watching very few television channels