Fuzzy based scheduling technique for multiple service flows in 802.16 WiMAX

摘要

In IEEE 802.16 WiMAX, it is a challenging task to achieve quality of service (QoS) by using scheduling technique as it requires understanding the traffic features and service requirements. Also most of existing works have considered only one of the service flows among rtPS, ertPS, nrtPS, UGS and BE. In addition, the existing priority estimation methods are not so accurate. To overcome these problems, in this paper, we propose a fuzzy based scheduling technique for multiple service flows in IEEE 802.16 WiMAX networks. This technique involves two entities namely evaluator and slot allocator. When the service flow enters into the network, the evaluator distinguishes the service flow as real time or non real time and estimates its priority using fuzzy logic technique. Then the evaluator arranges the real time and non real time service flows in two sub queues and then sorts them by their priority levels. The slot allocator obtains the priority information of service flows from the evaluator to allocate slots. By simulation results, we show that the proposed approach is better in terms of the measured channel utilization and received bandwidth for real-time and non real time flows.