Improvement of routing and wavelength assignment in WDM networks using tabu search

In this paper, we deal with the routing and wavelength assignment (RWA) problem for wavelength division multiplexing (WDM) networks containing permanent and reliable wavelength paths (WPs). This problem consists of finding the routes of the WPs and the wavelength assignment for the normal state of the network and for the important failure scenarios. These scenarios might be the most probable failure scenarios or simply the failure scenarios of interest to the network planner (e.g., the single link failure scenarios). More specifically, we analyze the effect of the value of the routing link metric vector on the solution cost defined has the total number of blocked WPs. We propose an algorithm based on the tabu search principle that tunes the routing link metrics in order to improve the solution cost.