Effective wavelength assignment algorithms in a wavelength-routed network

This paper addresses the problem of wavelength assignment and wavelength routing in a wide-area optical network, where Wavelength Division Multiplexing (WDM) technology has emerged as the transmission and switching choice. One of the major design issues in this network is the assignment of the limited number of wavelengths among network stations so that higher aggregate capacity can be achieved. The problem of wavelength assignment and routing is proved to be NP-hard problem. The present literature on this topic is a large repertoire of heuristics that produce good solutions in a reasonable amount of time. These heuristic, however, have restricted applicability in a practical environment because they have a number of fundamental problems including high time complexity, lack of scalability with respect to optimal solutions. In this paper, we propose genetic based algorithm with an objective to simultaneously meet the goals of height performance and fast running time. In addition, we propose to apply the Greedy Random Adaptive Search Procedure (GRASP) to solve the wavelength assignment problem. We demonstrate that our proposed algorithms can achieve lower blocking probability while taking considerably less running time when compared to one of the best known heuristic wavelength assignment algorithms proposed by Zhang and Acampora, in which close to optimal solution can be obtained.