Increasing throughput through reduced blocking probability in hybrid fault tolerant optical WDM networks

In WDM networks, failures may occur in node or link and hence all the fibers which involves the failed link, also fails. In order to protect against the failures, protection and the restoration fault tolerance methods can be utilized. But both of the methods include several demerits. In this paper, we propose to develop a hybrid adaptive algorithm for fault tolerance in survivable WDM networks which combines the positive effects of restoration and protection. In this algorithm, initially multiple light paths are established based on the current load and blocking probability. Also, based on the load changes of dynamic traffic, loads are adaptively shifted to other resource efficient light paths. The simulation results show that the proposed algorithm achieves reduced blocking probability thereby increasing the throughput as the time increases.