Traffic grooming in WDM mesh networks with guaranteed survivability

Traffic grooming techniques in optical networks are attracting increasing research attention in order to handle the huge bandwidth mismatch between high capacity lightpaths and low-rate individual traffic requests. It is important to have guaranteed survivability of all user connections in such networks. Path protection has emerged as a widely accepted technique for survivable WDM network design. However, it requires allocating resources for backup lightpaths, which remain idle under normal fault-free conditions. In this paper, we introduce a new design strategy for survivable traffic grooming in WDM networks, under specified resource constraints. Our approach addresses the complete design problem including logical topology design, RWA, and routing of (subwavelength) requests over the logical topology. We further ensure that the resultant logical topology is able to handle the entire traffic request after any single link failure. We first present two ILP formulations for optimally designing a survivable logical topology, and then propose a heuristic for larger networks. Experimental results demonstrate that this new approach is able to provide guaranteed bandwidth, and is much more efficient in terms of resource utilization, compared to both dedicated and shared path protection.