On static RWA in translucent optical networks

The distance an optical signal can travel before the signal quality degrades to a level that necessitates regeneration is called the optical reach. To establish a lightpath of length greater than the optical reach, it is necessary to regenerate optical signals at one or more nodes. In this paper we have proposed routing and wavelength assignment algorithms for translucent networks. For each request for a lightpath, the objective is to find a route from the source to the destination of the request, so that a translucent lightpath may be established that requires the fewest possible stages of regeneration. We have proposed an Integer Linear Programming (ILP) formulation that gives the optimum solutions for small networks. For larger networks, we have proposed an efficient heuristic. We have shown that the heuristic produces close-to-optimal solutions in a fraction of the time needed for the optimal solutions.