用digital hierarchy造句子，“digital hierarchy”造句

6、Temporary regulation for design of synchronous digital hierarchy(SDH)microwave relay telecommunication system engineering

2、Frame structure for synchronous digital hierarchy signal

5、Requirements for synchronous digital hierarchy (SDH) optical fiber cable line systems of national public telecommunication network

3、Basic multiplexing structure for synchronous digital hierarchy signals

1、Synchronous digital hierarchy bit rates

4、Specifications for synchronous digital hierarchy (SDH) multiplex equipment

7、Methods of measurement for synchronous digital hierarchy(SDH)optical fiber cable line systems