Split restoration with wavelength conversion in WDM networks

In this paper, we propose a path restoration algorithm for a single fiber fault in WDM network equipped with wavelength conversion. The integer linear programming (ILP) formulas for minimizing the path recovery cost can yield the optimum solution but it is NP-complete. Our heuristic algorithm relaxes the complexity by two steps. In the off-line step, the node-link topology is replaced by the node-wavelength topology, the alternate paths for source-destination node pairs are listed, and the wavelengths in each link are assigned by maximum matching. In the on-line step, traffics going through the failed link are split into subtraffics and are restored according to their priorities. The performance analysis and the simulation results indicate that out heuristic algorithm is practical for WDM networks restoration.