A quality of service mechanism for IEEE 802.11 wireless network based on service differentiation

This paper introduces an analytical model for wireless local area network with priority schemes based service differentiation. This model can predict station performance by access stations´ number and traffic type before wireless channel condition changed. Then a new algorithm, DTCWF (dynamic tuning of contention window with fairness), is proposed to modify protocol options to limit end to end delay and loss rate of high priority traffic and maximize throughput of other traffics. Simulations validate this model and the comparison between DTCWF, DCF, and EDCA shows that our algorithm can improve quality of service for real-time traffic.