Adaptive scheduling strategy for WiMAX real-time communication

Defined by the IEEE 802.16 standard, WiMax system is also called broadband wireless metropolitan area network. It supports real time and non-real time services. There is no packet-scheduling algorithms defined, which was need for the requirement of quality of service (QoS) supporting for real-time services. Normally, the service station (SS) requests for bandwidth from the base station (BS), The BS then allocates the bandwidth to SS according to priority-based request. In this paper we propose an adaptive bandwidth scheduling strategy for real time polling services (rtPS), the SS estimate the arrival of rtPS packets prior to the arrival and requests the BS for bandwidth in advance, based on the SS´s request and the actual bandwidth request by past. The analytical model and simulation show that, this adaptive algorithm provided better results with respect to the number of packets waiting at SS and average delay as compared to the widely accepted weighted scheduling algorithm and other adaptive bandwidth request mechanism.