A multi-objective approach for throughput optimization and traffic engineering in WDM networks

In this paper, we present a multi-objective Integer Linear Program (ILP) for the joint throughput optimization and traffic engineering problem in Wavelength-Division Multiplexing (WDM) networks. The proposed model simultaneously maximizes the aggregated throughput, minimizes the resource consumption, and achieves load balancing by minimizing the maximum link utilization (MLU). Even though the ILP is NP-hard, we demonstrate its application in a 14-node network. In addition to the ILP, we propose a heuristic algorithm which can be implemented in a distributed manner. The proposed algorithm addresses the multi-objective problem as an e-constraint problem, upper bounding the per-route resource consumption and maximizing the throughput by routing through multiple widest paths. Performance studies show that, by considering the multiple objectives simultaneously, the solutions of the ILP are better than those obtained by optimizing a single objective only. At the same time, the throughput of the heuristic is close to optimal, and load balancing is achieved. Furthermore, its resource consumption is nearly the same as the one obtained by the shortest path algorithm, which is optimal when only resource consumption is considered.