Efficient algorithm for removal of loopbacks in p ‐cycle‐based survivable WDM networks

Abstract

p-cycles have been widely investigated for survivability of wave division multiplexing (WDM) optical networks. It combines fast recovery feature of ring and spare capacity efficiency of mesh. However, it provides a longer restoration path (RP) which increases the transmission time and causes other impairments. Researchers in this field have mentioned that the loopbacks are the main reason behind the longer length of RPs. Two predominant algorithms have been reported in the literature for the removal of loopbacks (RLB). Both algorithms determine the loopbacks by the route information dynamically aggregated at incident nodes of the failed span. Dynamically acquiring route information of affected working paths and candidate p-cycles causes communication and node processing overhead. In this study, we have conducted an analytical study to ascertain the node which forms the longest loopback in RP. Further, an efficient algorithm has been proposed for RLB directly without gathering the route information and tedious loopback calculation at the end nodes of failed span. The simulation result shows that the proposed approach substantially reduces RPs length and promptly removes the loopbacks. Further, it has reduced communication and other overheads to a great extent.