Efficient channel reservation for backup paths in optical mesh networks

In an optical mesh network, backup channels are shared between multiple lightpaths to reduce restoration capacity overhead. The sharability of channels is usually constrained by the mandate to provide 100% recovery of all lightpaths affected by any single event failure in the network. This paper proposes a pool based channel reservation scheme that is optimal when the set of primary and backup paths (specified at link level without channel allocation) is given. In the online case, our simulations on representative network topologies show that this method improves over the existing (more restrictive) method of allocating shared backup channels using primary path diversity.