Date Added: Dec 2012
Quality of Service (QoS) is an ability to guarantee a certain level of performance to data flow in a wireless network. IEEE 802.11 a/b/g networks do not provide QoS for multimedia traffic. Where as providing QoS for IEEE802.11e is difficult. EDCA technique enhances the QoS service in IEEE802.11e. Enhanced Distributed Channel Access (EDCA) which is a contention-based channel access mode. With EDCA, high-priority traffic has a higher chance of being sent than low-priority traffic. EDCA provides contention free access to the channel for a period called a Transmit OPportunity (TXOP). The TXOP works on the basis of four Access Categories (AC) of EDCA. By varying the TXOP value and MAC parameters among the ACs the authors can get the Qos optimization.