An Efficient Packet Scheduling Algorithm for IEEE 802.16 BWA System
Channel quality has a great influence on bit error rate (BER) of received signal. The scheme to efficiently ensure four kinds of data services provided by IEEE 802.16 standards is an interesting research issue. In this paper, we propose an adaptive scheduling algorithm cross physical (PHY) layer and MAC layer for IEEE 802.16 BWA system. The Signal to Noise Ratio (SNR) on wireless fading channels determines the modulation and coding (AMC) scheme and the quantity of transmitted packets at the PHY layer. The objective of the AMC coding scheme is maximize packets throughput while maintaining the BER requirement. At the MAC layer, the algorithm scheduling the packets to ensure diverse QoS requirements for multiple connections, e.g., delay for rtPS, throughput for nrtPS, and fairness for BE. To obtain optimal scheduling, we define the cost function for each connection based on channel condition, service status, throughput or deadline. We also verify the analytic results using computer simulation. The simulation results show that our proposed scheduler can provide diverse QoS guarantees, maximum throughput and achieve an optimal tradeoff between throughput and fairness.