Preemption Scheme for Improving Source Level Fairness in Optical Burst Switching Networks

Due to the buffer-less characteristic in the data burst channels of optical burst switching (OBS) networks, the burst loss probability tends to be proportional to the hop count between the source and destination (distance fairness). In addition, in practical networks, network operators occasionally cannot provide a bandwidth proportional to the traffic in each link because of a resource limitation. This causes bottle-neck links and unfairness for bursts generated from different ingress switches (source level fairness). We propose a preemption scheme, called resource consumption based preemption (RCBP), to improve both distance and source level fairness in OBS networks. We performed simulations on a ring-based network to prove that RCBP increases the fairness index in terms of distance and source level fairness.