论文部分内容阅读
加拿大与辽宁邮电科研所合资生产光纤传输系统加拿大北方电讯公司与辽宁省邮电科研所合资生产高容量的同步数字分级（ＳＤＨ）光纤传输系统。同步数字分级是一种光学信号接口标准，适用于城市和地区之间传输数字话音、数字视像信号的光纤网络。同步数字分级传输系统为本地...
Canada and Liaoning Institute of Posts and Telecommunications joint venture to produce optical fiber transmission system Canadian Northern Telecom and Liaoning Province Posts and Telecommunications Research Institute joint venture to produce high-capacity synchronous digital hierarchy (SDH) optical transmission system. Synchronous digital grading is an optical signal interface standard for fiber optic networks that transport digital voice and digital video signals between cities and regions. Synchronous digital hierarchical transmission system for local ...