The Contention Resolution And Performance Analysis Of OPS With FDL And LRWC

Optical packet switching becomes a best solution of conquering electronic bottleneck owing to smaller switching granularity, higher switching speed and the support to the upper protocol. However, there are still a number of critical issues affecting the implementation of optical packet-switched networks. In this work, we have proposed solutions to critical issues in OPS networks: contention resolution. Several approaches, such as wavelength conversion, deflection routing, and optical buffering, have been proposed for resolving contention. Further more, we have also developed accurate analytical models to evaluate the performance for each proposed scheme.We focus on the performance of output buffering. Because the delay granularity has great influence on the performance of OPS, we must choose it carefully. We bring forward a formula to modify the optimal delay granularity: when the load is larger, we make the optimal delay granularity smaller; this can make the packet loss probability extremely lower.An optical packet switch with FDLs and Limited-range Wavelength Converters (LRWC) is focused in this paper, which supports asynchronous variable-length optical packets. We studied and discuss the relations between packet loss probability and the load, the number of the FDLs. The result shows that the introduction of the LRWC can reduce the number of the FDLs, and the performance of this network was improved greatly.