The development of China CATV can be roughly divided into three stages.
1974 rpm1983-With the increase of TV programs, * * appeared on the roofs of residential buildings or bungalows with antennas. This stage is the primary stage of cable TV development-* * * antenna stage. The technical feature of this stage is full-channel frequency division transmission, and a single antenna system can transmit five or six sets of TV programs.
From 1983 to 1990—— The local propaganda bureau of the former Ministry of Radio, Film and Television approved Beijing Yanshan Petrochemical Company 10000 cable TV network construction 1983. At the same time, marked by the opening of 1985 Shashi CATV network, CATV stepped out of the antenna stage and entered the CATV network. At that time, CATV was mostly a regional or enterprise closed-circuit system, so this stage can be called-closed-circuit television stage. The technical feature of the development at this stage is that enterprises or metropolitan area networks which are mainly wired adopt adjacent frequency transmission mode, and the number of transmitted programs is generally around ten sets. In some places, optical cables are used for long-distance transmission.
From1990165438+10.2, the Ministry of Radio, Film and Television promulgated the Interim Measures for the Administration of Cable TV, and China Cable TV entered the track of standardization and legalization. With the approval of 199 1 the Ministry of Radio, Film and Television to set up a cable TV station, China cable TV is really on the right track. At present, China CATV is developing in the direction of network industrialization.