Quality-of-Service Provisioning using Hierarchical Scheduling in Optical Burst Switched Network

The issues of providing QoS in WDM OBS network are attracting increasing attention in the networking community. One of the key issues is to design efficient algorithms for burst scheduling or more precisely their bandwidth reservation. An ideal scheduling algorithm should be able to process a control packet fast enough before the burst arrives, and yet be able to find a suitable void interval for the burst as long as there exists one. Otherwise, a burst may be unnecessarily discarded either because a reservation cannot be completed before the burst arrives or simply because the scheduling algorithm is not smart enough to make the reservation. In this paper, we propose an OBS network model using the per-hob-behaviors with its three methods of forwarding of the differentiated service to create the burst packets and to implement the burst hierarchical scheduling technique using weighted round-robin and priority queueing (WRR_PQ) in order for the network model to support QoS in terms of lower blocking probability, higher resource utilization and lower burst loss rates.