中文摘要：

首先针对方向性资源网络中单链路失效情况，提出了一种新型预配置保护（p）圈算法，即单方向p圈，通过为传统p圈加载方向性，分成顺时针p圈和逆时针p圈．然后针对单方向p圈提出了新的评价标准及其应用在方向性资源网络中的方法与步骤．通过仿真比较了单方向p圈与传统无方向p圈在方向性资源网络中的性能，结果表明在方向性资源网络中，单方向p圈比传统无方向p圈更具有优势，其可以充分利用所配置的保护资源，以较少的网络资源，实现较高的业务保护成功率，从而改善方向性资源网络中p—cvcle算法的性能．

英文摘要：

A new pre-configure cycle （p-cycle） algorithm named unidirectional p-cycle is proposed when considering the single span failure in mesh networks with directional capacity. Unidirectional p- cycle includes clockwise and counterclockwise p-cycle by adding direction to traditional p-cycle. The new evaluation criteria and approach for determining and configuring candidate p-cycles according to the proposed algorithm are presented. Extensive simulations show that the proposed unidirectional p- cycle outperforms conventional p-cycle algorithms in mesh networks with directional capacity in terms of protection success ratio, protecting capacity proportion and protecting capacity utilization .