The Survivability of the Augmented Logical Ring Topology in WDM Networks

The logical ring topology is a simple protection scheme in WDM networks. The failure of a single physical fiber link may cause the failure of multiple lightpaths. The service becomes unprotected if the failure propagates to the logical ring topology. In this paper, we focus on the elimination of failure propagation from the physical WDM network to the logical topology. We propose a method to make the augmented logical ring topology survivable. The augmented survivable edges (ASE) is based on the connectivity problem of the logical topology. Our method makes the modification of logical ring topology cost-effective, i.e., with the minimal number of the additional edges to the original logical ring topology. Finally, we show the results on various network cases