Within the framework that the IEEE 802.11e provides for quality of service (QoS) provisioning, effective admission control is required to ensure requisite delay and throughput for real time traffic. To this end, several admission control algorithms have been proposed. In this paper, we propose a measurement based admission control algorithm, with an aim to provide dynamic adaptability at low computational complexity, without reliance on complex analytical throughput calculation. The information of percentage drop at each station under heavy load is utilized to ensure acceptable performance for real time traffic. The proposed algorithm also provides prioritized QoS and presents considerable improvement over existing algorithms of similar complexity, striving at a balance between efficient channel resource utilization and service requirements.