Emission and Discard Priority scheme for optimized deflection routing in OBS networks

Resolving contention in an efficient and cost-effective manner is a key issue in optical burst switched (OBS) networks. Although deflection routing has been identified as a cost-effective solution, its viability has been questioned. We propose an emission and discard priority (EDP) scheme to alleviate the shortcomings of deflection routing. The objective of this EDP scheme is to reduce the number of late packet arrivals due to burst deflections and to increase the efficiency of deflection routing with selective burst deflections. Through simulation, we compare the performance of deflection routing using the EDP scheme with a basic deflection routing scheme and a no-deflection scheme. Simulation results show that the deflection with EDP scheme has a higher throughput than the basic deflection scheme for loads L ges 0.7 and has a lower proportion of late packet arrivals than the deflection scheme at all loads. We also find that the deflection with EDP scheme has higher goodput than the basic deflection scheme for loads L ges 0.7 . Furthermore, the deflection with EDP scheme has greater efficiency than the deflection scheme in terms of goodput per deflection.