Rollout algorithms for logical topology design and traffic grooming in multihop WDM networks

In this paper we consider the logical topology design and traffic grooming problem in multihop WDM networks. Usually, this problem is defined as an integer linear program (ILP) which is NP-complete. This justifies the use of heuristic algorithms. Many heuristic algorithms differ in the order of traffic demands considered for lightpath provisioning. We apply the technique of `rollout´ to systematically improve the performance of various heuristic algorithms by approximately optimizing the order in which traffic demands are considered. Through simulation experiments, we show that the performance of the rollout algorithms we derive are clearly superior not only to that of the initial heuristic algorithms on which they are based, but also to that of other well-known heuristic algorithms