Protocol enhancement for IEEE 802.11e EDCF

The support of quality of service (Qos) is a very important issue for the deployment of real-time multimedia applications over wireless networks. The upcoming IEEE 802.11e standard has introduced the EDCF acces7s mechanism to support service differentiation in WLAN. In this paper, we propose an adaptive continuous transmit EDCF (ACT-EDCF) protocol to enhance the performance of EDCF. It not only allows stations to transmit continuously according to the different traffic priorities, but also can dynamically change the contention window size and the continuous transmit limit according to the estimation of channel status. Through the comparison with the IEEE 802.11e EDCF, we demonstrate that ACT-EDCF can enhance the system throughput and utilize the channel more efficiently. It can also provide better service differentiation than standard EDCF.