PWCE design in survivablewdm networks using unrestricted shape p-structure patterns

We propose a new way to design a Protected Working Capacity Envelope (PWCE) in survivable WDM networks by using pre-configured protection structures with unrestricted shapes (arbitrary shape patterns). So far, the pre-configured cycle (p-cycle) structure is the only building block that has been used in the design of PWCEs. In this paper, we do not impose any restriction on the shapes of the protection building blocks, rather, we search for p-structures in the network that favor the protection efficiency (reliability, redundancy) and recovery delay (local recovery). In order to cope with the large solution space, we use an efficient large scale optimization technique that relies on Column Generation (CG) where only globally most promising p-structures are enumerated on the fly during the optimization process. We compare the capacity efficiency, the reliability, and the average length of the backup paths of our PWCE design approach with the p-cycle based one. The results show that a design based on unrestricted p-structure patterns is ∼ 10% less capacity redundant, ∼ 15% more reliable, and allow recovery along shorter backup paths compared to the p-cycle based scheme.