Efficient path selection and fast restoration algorithms for shared restorable optical networks

Efficient path selection combined with fast restoration algorithms is a key requirement for designing shared restorable mesh networks. In this paper we first discuss a distributed path selection algorithm for efficient routing of restorable connections in optical networks. This approach relies on the knowledge of global information, maintained at each node, to determine link sharability and compute optimal shared paths; we compare its performance to another protocol [C. Assi et al., 2002] that only requires the knowledge of local resource usage. Second, we study the network´s ability to recover from single element failures in a shared mesh network and we propose a new restoration algorithm for rapid recovery upon a failure. The significant contribution of this algorithm is that the network restoration time is independent of the protection path length (i.e., the effect of propagation delay is eliminated) as well as the accumulation of the switch configuration times. We evaluate the performance of these protocols through simulation experiments.