Supporting VoIP Services in IEEE 802.11e WLANs

Voice over Internet Protocol (VoIP) over Wireless Local Area Network (WLAN) is becoming popular thanks to its cost efficiency. How-ever, it has been a challenge to provide good quality of VoIP services in WLANs, which is due mainly to the nature of contention-based channel access of WLAN Medium Access Control (MAC); the presence of coexisting non-real-time data traffic; and the time-varying WLAN capacity caused by transmission rate diversity and variation of stations over time. This paper proposes a simple, effective and viable solution to improve the quality of VoIP services in 802.11e contention-based WLANs, which basically utilizes the advanced features of 802.11e MAC for QoS support.