SAFS: A Self Adaptive Fuzzy-Based Scheduler for Real Time Services in WiMAX System

A critical part of the IEEE 802.16e MAC layer specification is scheduling. The scheduling mechanism has a significant effect on the performance of WiMAX systems for use of bandwidth and radio resources. In this paper, we propose a self-adaptive fuzzy based scheduler, and call this approach SAFS which respectively, adjust priority and transmission Quantum to each connection by taking the packet head-of-line latency and channel conditions of real time service users into account. Since, the relation between traffic specifications and network state is uncertain in wireless communication environment, we proposed a self-adaptive fuzzy inference system (FIS) to deal with imprecise input variables. The simulation results show that our adaptive scheme satisfies the maximum delay requirement and Throughput among the real time service connections in mobile WiMAX systems.