On-demand flexible tiered qos scheduling algorithm for ieee 802.16j multi-hop relay networks

Abstract

WiMAX is a wireless technology that provides broadband access for services having different QoS requirements and different traffic priorities. Since the QoS demands of different traffic flows vary, it is the responsibility of the medium access control (MAC) layer to schedule the traffic flows and allocate bandwidth such that the QoS requirements of each flow is satisfied. This scenario is even more complex when multi-hop relays are introduced into the network. Nonetheless, the IEEE 802.16j standard does not specify any QoS architectures or scheduling mechanisms. In this paper, we propose an On-Demand Flexible Tiered (ODFT) QoS scheduling algorithm for WiMAX Multi-hop Relay networks to guarantee the QoS demands of various applications by utilizing QoS tiers for the relay network. The ODFT (1) classifies the user requests from various wireless zones based on the zone ID and service flow types, (2) calculate the QoS weights of the service flows, (3) schedule service flows based on the calculated weights, and (4) allocate suitable bandwidth for each service flow type.