Shared Path Protection in DWDM Mesh Networks

Failure of even a single fiber link in DWDM mesh networks can cause severe data and revenue loss due to failure of several lightpaths of high bandwidth. This paper investigates this problem using shared path protection technique. First, we propose a link disjoint path finding heuristic, Multiple Active Path Search (MAPS) and show that it works even under trap topologies where conventional algorithms fail. Then using it as routing heuristic, we assign wavelengths to each connection request as they arrive, to design RWA algorithms. Apart from this static routing, we also design an Adaptive Routing (AS) heuristic, which operates in case no wavelengths are available for the disjoint path pair found by MAPS. The numerical results obtained for random network topologies with static random traffic demands show that both fixed and adaptive routing algorithms outperform conventional algorithm, giving lower blocking probability in terms of traffic and maximizing one-hop protected traffic.