长途通信网

同步数字体系（SDH）和同步光纤网络（SONET）在世界范围广泛应用于城域主干网，长途通信网和广域网。

Synchronous Digital Hierarchy ( SDH ) and Synchronous Optical Network ( SONET ) are now applied worldwide both in carrier backbone networks , by metropolitan service providers and in large scale WANs by end-user organizations .

长途通信网汇接方案它汇集市场需求的信息。

Trunk switching scheme It collects information about market needs .

中国联通长途通信网的建设与发展

Construction and Development of China Unicom Long Distance Network

擅长临场发挥的演员.交通专用卫星长途通信网建成并实现了全国联网，在推进交通信息化方面发挥了作用。

The satellite telecommunication network specialized in transport has been set up and networked nationwide , greatly promoting the informationization of the transport sector .

一种长途通信电缆网干线监控系统的设计和实现

Design and Implementation of a NMCS on Cable Network