Two-link failure protection in WDM mesh networks with p-cycles

In WDM networks, it is important to protect connections against link failures due to the high bandwidth provided by a fiber link. Although many p-cycle based schemes have been proposed for single-link failure protection, protection against two-link failures have not received much attention. In this paper, we propose p-cycle based protection schemes for two-link failures. We formulate an ILP model for the p-cycle design problem for static traffic. We also propose two protection schemes for dynamic traffic, namely SPPP (Shortest Path Pair Protection) and SFPP (Short Full Path Protection). Simulation results show that SFPP is more capacity efficient than SPPP under incremental traffic. Under dynamic traffic, SPPP has lower blocking than SFPP when the traffic load is low and has higher blocking than SFPP when the traffic load is high.