We consider the problem of handling two-link failures in WDM mesh networks. Existing schemes either prereserve two backup paths for each demand or compute new backup paths for unprotected demands after the first link failure occurs. Both approaches require a large amount of backup capacity. In this paper, we propose a capacity efficient hybrid protection/restoration scheme for handling two-link failures. The protection component reserves backup capacity intelligently to ensure the majority of the affected demands can be restored using the pre-planned backup paths upon a two-link failure. For the rest of the affected demands, our restoration component dynamically finds new backup paths to quickly restore them. The capacity efficiency and protection/restoration capability of our hybrid scheme are demonstrated through numerical results.
['Lu Ruan', 'Taiming Feng']
A Hybrid Protection/Restoration Scheme for Two-Link Failure in WDM Mesh Networks