An improved downlink scheduling algorithm for VOIP traffic in IEEE 802.16

The IEEE 802.16 standard has defined several QoS scheduling types without detailed implementation of the bandwidth scheduling scheme. Since the DL direction is more likely to be bottleneck than the UL direction, in this paper, we propose an improved framework for downlink real-time traffic, which acquire packet information by cross-layer design and dynamic drops the packets according to the network status. In condition of congestion, the improved framework reduces the use of bandwidth and packet delay, optimizes the jitter and guarantees better QoS. In this paper we take VOIP traffic for simulation, and the results indicate that the optimized framework is able to improve the performance of the system after reasonable optimization to downlink packet queue algorithm.