Static Routing and Wavelength Assignment Inspired by Particle Swarm Optimization

The static routing and wavelength assignment (RWA) problem for wavelength routing optical networks has traditionally been solved using Integer Linear Programming (ILP) and graph colouring. These problem domain search schemes become inefficient for solving large NP-hard (Non Polynomial Time - hard) optimization problems and in dynamic environments because of their computational complexity and execution time. In this paper, a heuristic approach inspired by Particle Swarm Optimization (PSO) is proposed for solving static RWA. A new encoding scheme for members of the swarm population is proposed. To help the particles to converge towards an optimal solution quickly, a novel scheme is devised for route selection, during particle's search. In order to diversify the search in problem space, a special operation is proposed for the global best particle. The proposed scheme achieves a good solution in a significantly lower number of iterations as compared to other heuristic algorithms.