Contention resolution and burst assembly scheme based on burst segmentation in optical burst switching networks

In this paper, contention resolution scheme based on burst segmentation and deflection routing in the core node and composite burst assembly scheme at the edge node are proposed. In the core node, contention is resolved through incorporating prioritized burst segmentation with deflection routing scheme. The burst segmentation scheme allows the tail of original bursts or the head of contending bursts to be segmented. The segmented burst is scheduled on the optimum deflection path by deflection routing scheme. At the edge of the network, a composite burst assembly scheme combines packets of different classes into the same burst, placing the highest priority packets in the middle and low priority packets at the tail and the head of the burst. The priority lowers gradually from the middle of the burst to the ends. An analytical model is proposed to evaluate the contention resolution scheme through calculating packet loss probability and the normalized end-to-end delay. Results show that high-priority bursts have significantly lower packet loss probability and delay than low-priority. So the contention resolution scheme which incorporates burst segmentation with deflection routing tends to perform better than the scheme only with burst segmentation or deflection routing.