A naturally-inspired algorithm for Routing, Wavelength assignment, and Spectrum Allocation in flexible grid WDM networks

Flexible grid networks enable elastic bandwidth transmission with higher spectral efficiency. In this paper, we address the Routing, Wavelength assignment, and Spectrum Allocation (RWSA) problem in flexible grid networks with the goal of maximizing spectral efficiency. We design a novel algorithm using a hybrid application of naturally-inspired procedures such as genetic evolution and simulated annealing. The performance of the proposed sequential meta-heuristic algorithm is evaluated with existing solutions and a lower bound. Simulation results demonstrate that the proposed algorithm outperforms the existing solutions and performs very close to the lower bound. Furthermore, the algorithm converges to the optimization in a limited number of evolution and annealing iterations.