Dynamic Wavelength Routing in WDM Networks via Ant Colony Optimization

This study considers the routing and wavelength assignment problem (RWA) in optical wavelength-division multiplexed networks. The focus is dynamic traffic, in which the number of wavelengths per fiber is fixed. We attempt to minimize connection blocking using Ant Colony Optimization (ACO). The algorithm employed quantifies the importance of using length and congestion information in making routing decisions with the goal of reducing total network blocking. The ACO heuristic is shown to be a viable solution to the RWA problem. At high numbers of ants exploring the search space, the ACO algorithm achieves lower blocking rates than an exhaustive search over all available wavelengths for the shortest path.