Implementation of a hybrid burst contention resolution algorithm for optical burst switching networks

Abstract

Optical burst switching is one of the optical switching technologies beside optical circuit and optical packet switching. It is considered as the optical switching paradigm that can be used in the near future before the technology that will support optical packet switching becomes mature. Optical burst switching has many good features. However, issue specifically burst contention which results in burst loss still become unresolved issue. A major component in optical burst switched networks is the core node whose main functions are burst scheduling and contention resolution. As traffic on the network increases, the contention at the core nodes also increases. This usually leads to burst drop at the core node if no suitable contention resolution technique is used. Many contention resolution techniques have been proposed by researchers with varying burst loss performances. In this study, a hybrid burst contention resolution technique that is capable of reducing burst loss is developed. The new hybrid technique is composed of two parts; wavelength conversion and burst segmentation. These techniques are used in a strict order when contention occurs. Wavelength conversion will always be the first technique to be invoked in order to resolve contention whenever it occurs. A successful resolution of the contention by the first part of the hybrid technique implies that the second part is skipped otherwise it must invoke the second part which is the burst segmentation technique. This research experiments were conducted through extensive event-driven simulation. Results obtained from simulations using the hybrid technique showed the burst loss reduction. It is shown that the hybrid technique has resulted in to an improved overall network throughput.