Algorithms for allocating wavelength converters in all-optical networks

In an all-optical wide area network, some network nodes may handle heavier volumes of traffic. It is desirable to allocate more full-range wavelength converters (FWC's) to these nodes, so that the FWC's can be fully utilized to resolve wavelength conflict. In this paper, we propose a set of algorithms for allocating FWC's in all-optical networks. We adopt the simulation-based optimization approach, in which we collect utilization statistics of FWC's from computer simulations and then perform optimization to allocate the FWC's. Therefore, our algorithms are widely applicable and they are not restricted to any particular model or assumption. We have conducted extensive computer simulations on regular and irregular networks under both uniform and nonuniform traffic. Compared with the best existing allocation, the results show that our algorithms can significantly reduce: 1) the overall blocking probability (i.e., better mean quality of service) and 2) the maximum of the blocking probabilities experienced at all the source nodes (i.e., better fairness). Equivalently, for a given performance requirement on blocking probability, our algorithms can significantly reduce the number of FWC's required.