This paper considers the performance problem of VoIP over 802.11e WLANs caused by the unfairness between uplink and downlink as well as the inefficient EDCA. A novel medium access control scheme named BEDCA (Balanced EDCA) is presented, which provides service differentiation between the access point (AP) and the mobile stations (STAs) to enhance VoIP capacity. In BEDCA, the expression of AP's contention window is obtained which is a relative constant value independent of the participating STAs. The minimum contention window of the STAs is traffic-aware based on the proposed algorithm. The performance improvement of BEDCA is verified through intensive simulations and the results show the capacity improvement of 82.1% compared to EDCA.
A novel access scheme REF was proposed for 802.11e WLANs with the goal of improving the QoS of VoIP over WLAN by differentiating the service between the AP and STAs.
Boosting VoIP Capacity via Service Differentiation in IEEE 802.11e EDCA Networks
International Journal of Distributed Sensor Networks
Computer Science