Dependable WDM networks with reconfigurable edge-disjoint p-cycles

In this paper, we propose a fault tolerant mechanism on the optical WDM network design with edge-disjoint p-cycles (EDPC) that is reconfigurable according failure scenarios. EDPC is a special type of traditional p-cycles, that is, no common edges are allowed to exist between any two p-cycles. One p-cycle provides guaranteed protection against to single link failure, but it can´t protect against simultaneous failures to two links on one p-cycle. If failures of multiple links happen in such way, all working spans protected by the p-cycle will crumble down. Our method called local reconfiguration recovers the protection environment to enable its protection ability. The results show that the EDPC method can tolerate more link failures and improve the restoration efficiency for traditional p-cycles with the decrease of two working units for every two p-cycles. When the protection environment crumbles down, the local reconfiguration method can speed up the recovering time instead of time consuming scheme, which blocks whole network and takes reconfiguration.