ETSI PRETS 300 462-4-1998 传输和复用(TM).同步网络的一般要求.第4部分:同步数字体系(SDH)和准同步数字体系(PDH)设备同步用从时钟的定时特性
Transmission and Multiplexing (TM); Generic Requirements for Synchronization Networks; Part 4: Timing Characteristics of Slave Clocks Suitable for Synchronization Supply to Synchronous Digital Hierarchy (SDH) and Plesiochronous Digital Hierarchy (PDH) Equ