Composite Burst Assembly with High-Priority Packets in the Middle of Burst

In optical burst-switched (OBS) networks, packets are aggregated into bursts that are sent an offset time after the corresponding control packet. The process of aggregating high and low-priority traffic in the same burst is known as composite burst assembly, where high-priority and low-priority packets are placed at the head and the tail end of the burst, respectively. Such composite bursts are beneficial in order to resolve the contention by dropping low-priority packets when preemptive minimum overlap channel (P-MOC) scheduling algorithms are used. For non-preemptive minimum overlap channel with void-filling (NP-MOC-VF) scheduling algorithm, we propose that highpriority packets should be placed in the middle of a burst and low-priority packets at the head and tail ends of a burst. That allows dropping of low-priority packets from the head and the tail of a burst when it contends with two other bursts where the head of the burst contends with one burst and the tail contends with another. The simulation results show that high-priority traffic faces reduced loss at the cost of increased loss of lowpriority traffic. In this paper, the effect of varying the proportion of high-priority packets in the middle of the burst has been studied.