An embedded fuzzy expert system for adaptive WFQ scheduling of IEEE 802.16 networks

• A 3×1 fuzzy expert scheduler embedded in base station of WiMAX is proposed.
• Latency, throughput, queue-length share are input and weight is output variable.
• Scheduling decision based on immediate values of variables mined during simulation.
• System maintained appreciable performance levels under heavy load conditions.
• Non-real time classes performance shows improvement as compared to EDF, WRR, WFQ .

WiMAX is a futuristic technology which provides simultaneous support for web, video, and voice applications. WiMAX networks are best suitable to real time traffic however the quantity of non real time and best effort traffic cannot be neglected. Distribution of resources in such heterogeneous applications is therefore a challenging task. There are many schedulers available for WiMAX but adaptive and adequate schedulers are still in growing stage of development. This paper introduces a novel method using which a system is developed based on concepts of fuzzy logic to schedule traffic in WiMAX networks. The proposed fuzzy expert system simplifies fair allocation of resources to real as well as non real time traffic. The implementation is based on changing the weights of the queues serving real and non- real time traffic adaptively. New weights will be calculated for each bandwidth request made to base station and these weights will in turn decide amount of bandwidth allocated to different traffic classes. The weights are calculated based on three parameters that are amount of real time and non real time traffic in queues, change in throughput requirement for non real time flows and latency requirement of real time input data. Results obtained by virtue of simulations justify the significance of the proposed method.