Techniques to Improve Performance of VoIP Over 802.11e WLAN
Voice over Internet Protocol is an important service with strict quality of requirements in Wireless Local Area Network (WLANs). The IEEE 802.11e standard has been introduced recently for providing Quality of Service (QoS) capabilities in the emerging Wireless Local Area Networks. This 802.11e introduces a contention window based that is Enhanced Distribution Channel Access (EDCA) technique that provides a prioritized traffic to guarantee minimum bandwidth needed for time critical applications. However this EDCA technique resets statistically the contention window of the mobile station after each successful transmission. This static behavior does not adapt to the network state hence reduces the network usage and results in bad performance and poor link utilization whenever the demand for link utilization increases.