Performance Improvement Methods for Burst-Switched Networks

In this paper, we present a performance model of optical burst switching (OBS) that can explain the degradation of OBS throughput performance when the control packet processing time increases. We then use the proposed performance model to investigate three feasible methods to improve OBS performance without significantly increasing the implementation complexity: addition of simple fiber delay lines (FDLs), random extra offset time, and window-based channel scheduling (WBS). Additional FDLs can eliminate the negative impact caused by the variation of the offset time between control packets and data bursts. The random extra offset time approach does not require any additional hardware and computational capability in the nodes. If higher computational capability is available, WBS in general can provide better throughput improvement than that of random extra offset time when FDLs are used in the nodes to compensate the processing time. Simulation results show that a combination of the proposed methods can significantly improve OBS performance.