Optimal Design of Delay-Bounded WDM Networks using a Genetic Algorithm

Abstract

We address the problem of real-time delay-bounded multicasting in wavelength-division multiplexed networks to avoid problems of synchronization between video and audio frames. We describe a genetic algorithm based technique to synthesize WDM network topologies that can, with a very high degree of confidence, assure that the multicast traffic is delivered in user-specified limits on time. Unlike existing approaches to WDM network design, we first find a virtual topology that can meet the delay constraints. An embedding of virtual links into physical links is then carried out, followed by an assignment of wavelengths to virtual links.The problem of finding the virtual topology is difficult because of a large number of parameters. A number of heuristic approaches have been proposed to solve such optimization problems. In our approach we aim to explore the suitability of Genetic Algorithms to solve the WDM network design problem. A genetic algorithm can explore a far greater range of potential solutions to a problem than do conventional approaches. The advantage of a genetic algorithm, compared with other algorithms which use a single initial guess e.g. gradient, descent is to use more information of estimation region, and to decrease the probability of falling into local minimum. We describe quantitative and qualitative results obtained by using our software tool on several benchmark examples.