Service Criticality Based Scheduling for IEEE 802.16 WirelessMAN

IEEE 802.16 WirelessMAN (WiMax) has emerged as broadband wireless access (BWA) solution for fixed and mobile communication requirements in the metro area. While the 802.16 standard throws adequate light on aspects of bandwidth-request and subsequent grants as well as supported service types, it however does not discuss service scheduling. In this paper, we propose a new scheduling algorithm, referred as service criticality (SC) based scheduling scheme. The SC scheme offers fairness, efficiency and low-latency scheduling and facilitates QoS guarantees. SC is based on a dual of buffer occupancies at nodes and allowable latencies for a particular service. We compare SC scheme with round-robin and max-min fair scheduling schemes under different system loads. We observe that while round robin and max-min scheme does not guarantee QoS support at high loads, the SC scheme facilitates efficient scheduling even at heavy loads. Simulation based study is reported that considers a multitude of services using realistic physical and MAC layer models. Delay and blocking results are investigated. The SC concept shows betterment over conventional max-min scheme as well as round robin.