Performance Analysis of Ieee 802.11e Edca with Qos Enhancements through Adapting Aifsn Parameter

Enhanced Distributed Channel Access is a priority mechanism which supports access category (AC) wise QoS by differentiating initial contention window (CW) size and arbitration inter-frame space (AIFS) time. EDCA has fixed range of CW and AIFS that has been chosen initially. In contemporary EDCA model AIFS parameter for each AC remains static, irrespective of number of stations in a network. We propose a scheme where we vary AIFS time of each access category, depending on current congestion on network. The proposed model incorporates a mechanism where AIFS wait is smaller if there are fewer stations contending and moves to more AIFS wait time in case of many stations willing to transmit. Simulations are also conducted to validate our suggested enhancements for AIFSN parameter.