| 1. | Pdh plesiochronous digital hierarchy
准同步数字体系 |
| 2. | Pdh : plesiochronous digital hierarchy
准同步数字系列 |
| 3. | Plesiochronous digital hierarchy
准同步数字架构 |
| 4. | Training - based simulation model and algorithm of plesiochronous digital hierarchy fiber communication system
基于训练的准同步数字系列光纤通信系统仿真模型与算法 |
| 5. | The sdh ( synchronous digital hierarchy ) is originally developed from the pdh ( plesiochronous digital hierarchy )
它是目前光纤通信系统中应用最广泛的数字传输体制。 |
| 6. | Sdh ( synchronous digital hierarchy ) has some primary advantages such as synchronous multiplexing , standard optical interface and strong network management compared with pdh ( plesiochronous digital hierarchy )
同步数字体制( sdh )与传统的伪同步数字体制( pdh )相比,有三大核心优势,即同步复用、标准光接口和强大的网管能力。 |
| 7. | Before the 1990s , the digital transmission equipment was based on the technical standards of plesiochronous digital hierarchy ( pdh ) . in order to connect the switch to pdh transmission equipment , the switch side needs lots of terminal equipment of the primary rate , i . e . , 2048 kbits ( 2m ) switching terminal circuits in compliance with itu - t standards ( e . g . s1240 s dtm trunk module and axe10 s etc module ) and ansi - standard - based 1544 kbits ones
在90年代初期以前，数字传输设备是建立在pdh （ plesiochronousdigitalhierarchy ）技术标准上，为了连接交换机到pdh传输设备上，在交换机侧需要大量的符合基群速率的终端设备，即符合itu - t标准的2048kbits ( 2m )交换终端电路（如s1240的dtm中继模块， axe10的etc模块）和符合ansi标准的1544kbits交换终端电路等。 |
