有线电视以其便于传输、损耗小、质量好、容量大、可双向传送等显著特点,受到社会的普遍欢迎。但县级有线电视网络在建造初期由于资金,技术和初级阶段用户的需求影响,所建的网络急需进行双向改造,对县级有线电视网络双向网改造作的必然性和技术作理性的探讨。 Cable TV is universally welcomed by the society for its distinctive features of easy transmission, low loss, good quality, large capacity and bidirectional transmission. However, in the early stage of the construction of county-level CATV network, due to the capital, technology and the needs of users in the initial stage, the constructed network urgently needs to be transformed in two directions. The inevitability and technical rationality of the two-way network transformation of county-level CATV network are discussed.