A novel scheduling algorithm for optical burst switched networks

Abstract

Optical burst switching (OBS) is an emerging technology that allows variable size data bursts to be transported directly over DWDM links. In order to make OBS a viable solution, the wavelength scheduling algorithms need to be able to utilize the available wavelengths efficiently, while being able to operate fast enough to keep up with the burst incoming rate. When implemented in hardware, the running time of the well-known horizon scheduler is O(1) for practical numbers of wavelengths. Unfortunately, horizon scheduling cannot utilize the voids created by previously scheduled bursts, resulting in low bandwidth utilization. To date, Min-SV is the fastest scheduling algorithm that can schedule wavelengths efficiently. However, its complexity is O(log m) and it requires 10log m memory accesses to schedule a single burst. In this paper, a novel modified Horizon scheduling algorithm with minimum reordering effects (MHS-MOE) in OBS networks has been proposed. Simulation results have shown that the proposed algorithm runs much faster than Min-SV and is significantly simpler than Min-SV in terms of complexity. Thus, the proposed algorithm proves to be well-suited for high speed networks applications. © 2010 Elsevier B.V., All rights reserved.