【摘要】 简述了北京本地传输网络近年来的发展，介绍了目前北京并存的ＰＤＨ网和ＳＤＨ网的主要特点及结构，提出了下一步对北京本地传输网发展的一些设想及有待进一步讨论的问题。更多还原

【Abstract】 Briefly describes the development of local transmission network in recent years, as well as the main features and network structure of PDH and SDH networks which are currently coexisted in Beijing ar eas. Sugests some matters relating to future development of Beijing transmission network and matters should be further studied.更多还原