下一代SDH传送网的关键技术

介绍支持数据业务的下一代同步数字体系(SDH)所用关键技术(通用成帧规程(GFP)、虚级联(VC)和链路容量调整方案(LCAS))的主要技术特点,比较了使用VC技术前后的带宽利用率;重点阐述LCAS帧结构各字节的含义及其表示方法,介绍LCAS的实现方式和链路容量调整的详细过程;最后分析LCAS技术在自动交换光网络(A-SON)中的作用及商用实例。LCAS与VC、GFP结合,能使新一代SDH网络更好地支持二层交换业务,全面适应数据业务的需求,在现有传输网上实现ASON的某些功能,逐渐过渡到智能光网络。

Key Technologies in Next Generation SDH

This article presents the main technical characteristics of next generation SDH key technologies that support data operation, namely generic frame procedure (GFP), virtual concatenation (VC) and link capacity adjustment scheme (LCAS). Bandwidth utilization before and after using VC are compared and then meaning and method of indication of each byte in the LCAS frame structure are expatiated. The way of implementation of LCAS and the detail procedure of link capacity adjustment are described. Finally, the function of LCAS technology in automatic switched optical network (ASON) is analyzed and its commercial implementation case studied. Due to the fact that LCAS, VC and GFP have enabled better support of level two switched services by the new generation SDH network, global data services can be adopted. By implementing certain functions of ASON in the current transmission network, gradual transition to intelligent optical network could be realized.