Particle Swarm Optimization for Routing and Wavelength Assignment in Optical Networks

In this paper, we demonstrate the use of particle swarm optimization (PSO) to obtain near-optimal solutions to the NP-complete routing and wavelength assignment (RWA) problem in optical networks. More specifically, our PSO algorithm solves the RWA problem to carry the given traffic demands so that the network wavelength requirement as well as the average path lengths for the traffic is minimized. We have developed a Java based network simulator that uses our PSO algorithm to do RWA and present results of our experiments on a variety of hand-crafted and real-world networks. We compare our results with well-known theoretical results for the lower bound on the number of required wavelengths and average path lengths, and show that we can achieve optimal results in some cases and near-optimal in others, thus demonstrating the usefulness of our PSO technique. To the best of our knowledge this is the first time PSO has been used to solve the RWA problem.