Segmented protection paths in WDM mesh networks

Wavelength division multiplexed (WDM) networks have matured to provide a scalable data centric infrastructure, capable of delivering flexible, value added, high speed and high bandwidth services directly from the optical (WDM) layer. Several existing methods attempt to guarantee recovery in a timely and resource efficient manner. These methods are centered around a priori reservation of network resources, called spare resources along a node disjoint protection path. We propose an efficient algorithm to select routes and wavelengths to establish dependable connections (D-connections), called segmented protection paths. Our algorithm does not insist on the existence of totally disjoint paths to provide full protection. We prove that: (1) whenever there exist two disjoint paths between a source and destination in a network, then a segmented protection path exists for any primary path chosen between them, while end-to-end protection paths are not guaranteed to exist; (2) the segmented protection path generated by the segmented protection path selection algorithm is the minimum segmented protection path; (3) the complexity of our algorithm is the same as the shortest path finding algorithm.