Soft Computing Techniques to Solve the RWA Problem in WDM Optical Networks with ILP Formulations

Abstract

This paper focuses on Integer Linear Programming formulations for the Routing and Wavelength Assignment problem in Wavelength Division Multiplexed optical networks where end-users communicate with each other by establishing all optical WDM channels which are referred to as lightpaths. The RWA problem is reducible to Graph Coloring problem in polynomial time and hence found to be NP-complete. So, Soft Computing techniques, Approximation schemes and Heuristic approaches can be applied to solve the RWA problem. In this work, we propose new ILP formulations by imposing additional constraints to the objective function, thus establishing lightpaths which are immune to signal distortion and crosstalk. After modeling the RWA problem as an optimization problem, we focus on applying Soft Computing techniques like Genetic Algorithms to find a sub-optimal solution for the RWA problem.