论文部分内容阅读
室内SLIC将实现电话与数字通信系统的连通除了传统的高压(75V有效交流电压)振铃信号之外,当今的电话和其它一些电话设备还需要对来自众多数字通信系统—ISDN(综合业务数字网)、WLL(无线本地环路)、电缆电话、DSL(数字用户环路)和光纤网的振铃信号做出反应。不幸的是,所需的振铃信号发生电路技术使费用增加、设计难度也增大。
Indoor SLICs will enable telephony to be connected to digital communications systems In addition to the traditional high voltage (75V effective ac voltage) ringing signals, today’s telephones and other telephony devices also need to communicate information from many digital communications systems - ISDN (Integrated Services Digital Network ), WLL (wireless local loop), cable phone, DSL (digital subscriber line), and fiber network. Unfortunately, the required ringing signal generation circuit technology increases the cost and the design difficulty increases.