Second Phase Reconfiguration of Restored Path for Removal of Loop Back in P-Cycle Protection

P-cycles are one of the most promising techniques used for span protection in optical networks. However when p-cycle is used to provide protection to any failed span, there may be overlapping of some nodes in the working path and in the restoration path provided by the p-cycle. These nodes are repeated in the restored path; hence redundant link capacity is used. These repetitions will form loops at the overlapping nodes. To remove these loops and release the redundant capacity, an algorithm is developed to reconfigure the restored path. This aspect of the p-cycle has not been discussed so far in the literature. The capacities required without reconfiguration and after reconfiguration have been compared. It has been found that with reconfiguration, considerable amount of capacity can be released, and the restored path length can also be reduced significantly