STM-N的结构 STM-N－Synchronous Transport Module level N，同步传输模块n级 STM-N信号帧结构的安排应尽可能使支路低速信号在一帧内均匀地、有规律地分布。为什么呢？。
求英语达人帮忙翻译一段话，中译英 With information society's coming，people hope modern information transmission network to provide various circuit and business quickly，economically and effectively，as the original network technology for its monotonic business and complex extension，the bandwidth limitations，it's already useless to modify or perfect in original framework，at the same time，the production of SDH and relies on its many characteristics，it come at a huge development in the WAN fields and Private network areas.SDH(Digital Synchronous Hierarchy)frame structure arranged for the rich of network overhead bytes for operation，management and maintenance.Generally speaking，these spending bytes mainly includes section overhead(SOH)and Path Overhead(POH).SOH can divide into Regenerator Section Overhead(RSOH)and Multiplex Section OverHead(MSOH)，Path Overhead can also be further divided into Higher order Path Overhead andLower order Path Overhead，respectively applied for the management and maintenance of faults and。
SDH传送网帧结构是怎样的呢？ SDH帧结构是实现SDH网络功能的基础，便于实现支路信号的同步复用、交叉连接和SDH层的交换，同时使支路信号在一帧内的分布是均匀的、有规则的和可控的，以利于其上、下电路。
