Traffic Grooming in Optical WDM Mesh Networks

Wavelength division multiplexing (WDM) has emerged as the preferred technology for reducing the opto-electronic bandwidth mismatch by dividing the bandwidth of an optical fiber into multiple non-overlapping wavelength channels, each operating at peak electronic speed of the end users. Traffic grooming is being considered as a key functionality of WDM networks, in which, multiple low-speed traffic requests are groomed onto a single, high-capacity lightpath (wavelength). Mathematical formulation of the traffic grooming problem has been developed for various optimization objectives. The present work focuses on the traffic grooming problem in WDM mesh networks under static traffic scenario, for optimizing network revenue. We have verified ILP formulation for the problem using CPLEX 9.1 and have developed three heuristics algorithms for solving the traffic grooming problem while optimizing network revenue. Performance of the three algorithms has been evaluated and a comparative study with the results of solving the ILP model has been carried out. The algorithms have been found to give good performance, especially for larger-sized networks.