本论文在简要阐述了各种光纤数字传输系统技术及其原理的基础上，通过比选确定出了符合钦州至崇左路段的较先进的光纤数字传输系统方案，确定其光纤通信系统采用SDH传输方案。在SDH传送网分层模型的基础上，对SDH传送网各层功能、信号流程、网络配置作了详细的阐述，同时说明了SDH传送网特有的复用映射原理。根据钦州至崇左路段的实际情况计算确定了系统中的重要参数，选择出了网络拓扑结构，按最坏值设计法进行了中继段长度的计算，编制了网络组织图、通道组织图及通信系统总体框图等。所设计的的高速公路光纤数字传输系统达到了能够同时传输语音、数据及图像的要求，并且满足了容量要求，实现了与相邻高速公路通信系统的相互连接。-The article,through compared to elects to determine,has conformed to Qinzhou to the Chongzuo road section ,which advanced optical fiber　digital transmission system plan, had determined the optical fiber communications system using the SDH transmission plan in the principle foundation.In the SDH transmission network model foundation, each function of SDH transmission network,the signal flow simultaneously　explained the　SDH transmission network which uniqued multiplying mapping inciple.The computation had determined the system important　parameter,had carried the worst value design law,the channel drafted　pattern and the communications system overall diagram and so on. The highway optical fiber digital transmission system, hadbeen designed had achieved simultaneously transmiting the pronunciation on,the data and the image requestion has satisfied the capacity which has realized neighboring highway communications system mutual connection.

Keywords： Expressway communication system　O