Fast and resource efficient segment-based failure recovery in WDM optical mesh networks

In this paper, we consider the problem of providing fast and resource efficient failure recovery in wavelength division multiplexed (WDM) optical networks under single link/node failure for dynamic traffic demand. We develop two novel segment-based schemes to achieve fast and resource efficient failure recovery. They include: 1) segment-based protection scheme in which resources are reserved for primary paths and protection paths at the time of connection establishment and 2) segment-based restoration scheme in which backup resources are not reserved in advance and a new backup path is computed only upon a failure. We conduct extensive simulation experiments on mesh 10/spl times/10, 11/spl times/11, and 12/spl times/12 networks to evaluate the proposed segment-based failure recovery schemes in terms of average recovery time, average spare capacity required for protection/restoration paths, and recovery ratio, for different network configurations. The numerical results obtained from the simulation experiments indicate that the segment-based protection provides significant savings (up to 30%) in spare capacity utilization over the end-to-end protection scheme. The average recovery time for the segment-based failure recovery schemes is significantly less (up to 35%) than that of the end-to-end failure recovery schemes. Furthermore, the recovery ratio for segment-based restoration scheme is considerably larger (up to 9%) than that of the end-to-end restoration scheme.