Burst-cluster transmission: service differentiation mechanism for immediate reservation in optical burst switching networks

In this article we propose a service differentiated burst transmission called burst-cluster transmission to provide service differentiation in terms of burst loss for optical burst switching networks. The proposed method consists of a burst assembly algorithm and burst transmission scheduling, and it works only at the ingress edge node. A mixed timer/burst-length-based assembly algorithm is considered for burst assembly, and bursts with different service classes are assembled simultaneously according to the algorithm. A burst-cluster is generated so that the bursts in the cluster are arranged in order from lowest priority to highest. Then the burst-cluster is transmitted according to the burst transmission scheduling. We also consider the application of burst-cluster transmission to delay-sensitive traffic. We evaluate by simulation the performance of the burst-cluster transmission for NSFNET. Numerical examples show that burst-cluster transmission succeeds in providing different service grades even though the burst loss probabilities of high-priority service classes are affected by the traffic load of low-priority ones