Efficient Traffic Grooming Scheme for WDM Network

Abstract

One major objective in WDM network design is to develop a logical topology and a routing scheme over the topology that minimizes the congestion of the network. This combined topology design and traffic grooming problem becomes computationally intractable, even for moderate sized networks. One standard approach is to decouple the problem of logical topology design and the problem of routing over the logical topology. Heuristics for finding the logical topology exist and a straight-forward linear program (LP), based on the node-arc formulation is normally used to solve the routing problem over a given logical topology. However, the traffic grooming problem is in itself an inherently difficult problem, and standard LP formulations are not able to solve this problem for large networks. In this paper,we have introduced a novel approach for traffic grooming, over a given logical topology, using the concept of approximation algorithms. This technique allows us to efficiently route traffic for practical sized networks and obtain solutions, which are guaranteed to be within a specified bound of the optimal solution. Simulation results from different networks demonstrate that approximation algorithms can be used to quickly generate “near-optimal” solutions to the traffic routing problem in WDM networks.