Offline routing and wavelength assignment for identification of regeneration sites in translucent WDM optical networks

The enormous data carrying capacity and speed of optical WDM networks, have made it an obvious choice for voluminous and high speed data communication. The optical signal can only propagate up to a certain distance (optical reach) retaining its characteristics. Before its quality starts to degrade below a threshold level, it needs to be re-amplified, re-shaped and re-timed using a 3R-regenerator. In this paper, we propose an offline scheme of Routing and Wavelength Assignment (RWA) of connection requests to reduce the number of regeneration sites in a translucent optical network to the extent possible. We compare the performance by of our algorithm with that of an Integer Linear Program (ILP) formulation. We compare the number of regeneration sites computed and channel capacity required for satisfying a given traffic matrix. Performance comparisons show that our algorithm RWA-MRS (RWA to Minimize Regeneration Sites) is able to provide near optimal solution in polynomial time.