Dependable WDM networks with edge-disjoint p-cycles

In this paper, we propose a fault tolerant mechanism on the optical network design with edge-disjoint P-cycles (EDPC). EDPC is a special type of traditional P-cycles, that is, no common edges are allowed to exist between any two P-cycles. Previously published schemes for computing P-cycles are time consuming and do not survive multiple link failures when P-cycles have common edges. Instead of using the complex ILP, a heuristic method based on link state routing which is compatible to the traditional open shortest path first (OSPF) network protocol is proposed to speed up the construction of EDPC. 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.