ملخص: In this paper we address the problem of constrained optimization (ILP formulation) and propose a set of heuristic algorithms for assigning light-trails [1–4,7,10] to WDM ring networks to facilitate IP centric dynamic communication at the optical layer. A light-trail is a generalization of a lightpath such that multiple nodes can take part in communication along the path without the need for optical switching. A light-trail represents an opportunistic medium in which multiple spatially distributed sub-lambda .ows can be groomed despite without the need for optical switching. A light-trail is analogous to an optical bus such that multiple connections between source–destination pairs can be provisioned under the constraint that no two connections have overlapping time-intervals. This enables tra.c grooming at the optical layer. In this paper we .rst describe a constrained optimization procedure for assigning light-trails in WDM ring networks. We then show .ve heuristic algorithms that solve the light-trail assignment problem in polynomial time. The heuristic algorithms are based on dynamic (unknown tra.c) and static (known tra.c) approaches. A simulation study compares the performance of ILP and heuristic algorithms.

لغة: إنجليزية