Guaranteed non dropping mechanism deploying IEEE802.11e standard

Recently, many people enjoy accessing wireless network to conveniently collect their required information or happily surf within the Internet worldwide by exploiting wireless mobility, flexibility and availability. However, the more sessions accessing the channel, the more packet dropping rate. In this paper, we propose a polling access control scheme which in its PCF mode deploys non-preemptive priority to efficiently transfer voice traffic which characterized by packet rate of voice source and the maximum tolerable jitter (packet delay variation) is forecasted. We also record the scheduling results in a queue, with which AP (Access Point) can poll and then enable mobile users to communicate with their opposite sites. This occurrence solves the problem that some voice packets do not suit QoS in IEEE 802.11e standard with multi-polling. While no voice packet can be transmitted, the scheme changes to DCF mode to transfer data packets. Furthermore we simulate and analyze the performance of the scheme in a WLAN environment. The experimental results show that our mechanism significantly improves packet dropping rate.