Fairness Enhancement Scheme for Multimedia Applications in IEEE 802.11e Wireless LANs

Multimedia traffic should be transmitted to a receiver within the delay bound. The traffic is discarded when breaking its delay bound. Then, QoS (Quality of Service) of the traffic and network performance are lowered. The IEEE 802.11e standard defines a TXOP (Transmission Opportunity) parameter. The TXOP is the time interval in which a station can continuously transmit multiple data packets. All stations use the same TXOP value in the IEEE 802.11e standard. Therefore, when stations transmit traffic generated in different multimedia applications, fairness problem occurs. In order to alleviate the fairness problem, we propose a dynamic TXOP control scheme based on the channel utilization of network and multimedia traffic quantity in the queue of a station. The simulation results show that the proposed scheme improves fairness and QoS of multimedia traffic.