Path-based protection for surviving double-link failures in mesh-restorable optical networks

We consider path-based protection methods for two-link failures in mesh optical networks. Two link-disjoint backup paths are pre-computed for each source and destination node pair. We identify the scenarios where the backup paths can share their wavelengths without violating 100% restoration guarantee (backup multiplexing). We use integer programming to optimize the total capacity requirement for both dedicated-and shared-path protection schemes. Our results indicate that backup multiplexing significantly improves the efficiency of total capacity utilization. For the randomly generated demand sets, the shared-path scheme provides up to 37.5% saving in total capacity utilization over dedicated-path scheme. Backup multiplexing provides more saving for the demand set that has connection requests distributed more evenly. For the double link failure recovery methods, path-based methods are more efficient in capacity utilization than link-based methods. Dedicated-path scheme performs better than shared-link scheme in total capacity utilization on average.