A Joint Transmission Grant Scheduling and Wavelength Assignment in Multichannel SG-EPON

Abstract

We investigate the problem of grant scheduling in multichannel optical access networks using a scheduling theoretic approach. The network we consider is a novel cost-effective Ethernet Passive Optical Network (EPON) that is designed to operate with STARGATE or any evolutionary MAN. We show that the problem can modeled using an Open Shop model and we present a formulation for the joint scheduling and wavelength assignment problem as a mixed integer linear program (MILP) whose objective is to reduce the length of a scheduling period. Since the problem is shown to be NP-Hard, we introduce a tabu search based heuristic for solving the joint problem. Different other heuristics are also introduced and their performances are compared with those of tabu and MILP. Results indicate that by appropriately scheduling transmission grants and assigning wavelengths, substantial consistent improvements may be obtained in the network performance.