With the quick development of wireless network,the flow on the network is increasing.How to improve service quality of the real-time flows in wireless local area network is becoming more important.Based on analyzing the MAC access mechanism and the limitations of providing service quality in IEEE802.11e WLAN,this paper proposes a new algorithm,PCWA(Practical Contention Window Adjustment) algorithm.Compared with the EDCA mechanism,the average delay for realtime flow is decreased apparently and capacity is im...