Double Link Failure Protection using a Single P-cycle

Abstract: In this letter, we investigate survivability in optical networks for protection from two simultaneous link failures. Failure probability of two links with overlapping protection can be high if these links are geographically close. In a network with deterministic single link protection, simultaneous failure of two links may lead to partial or full loss of traffic on the failed links. Two link failure protection will make the network more resilient by protecting double failures having overlapping protection. A method for achieving double fault tolerance is double cycle method (DB); it uses two pre-configured cycles (p-cycles) to protect a link. Single p-cycle (SG) method, which uses one p-cycle to protect a link from two simultaneous link failure is introduced in this letter. Integer linear programs (ILP) are formulated for the SG method as well as DB method. It has been observed that the SG method provides a solution to bigger networks with lesser computational resources as compared to the DB method.