Click to edit Master title styleClick to edit Master text stylesSecond levelThird levelFourth levelFifth levelLecturer: Dai Zhibao华为 OptiX光传输系统SDH 原理SDH概述——建立SDH概念SDH信号帧结构和复用步骤开销和指针设备的逻辑构成课程介绍内容PDH固有缺