【摘要】 从改善WLAN的尽力而为服务为出发点,简单介绍了DCF﹑EDCF和PCF,并分析了它们对尽力而为服务的机制和弊端。在此基础上,讨论了竞争窗口对系统总吞吐量和尽力而为服务的影响,从提高公平性﹑加大吞吐量的角度,提出了运用动态优先权来降低尽力而为业务的接入时延,并仿真得出结论。更多还原

【Abstract】 In order to raise the QoS of WLAN,we take a serious of measures.The IEEE802.11 Distributed Coordination Function(DCF) offers only best-effort services.The Enhanced DCF(EDCF) supports QoS by establishing a probabilistic priority mechanism to access the shared wireless medium.In this paper,we simply analyse EDCF and PCF mechanism to assure the premise of QoS of real-time services and play down the QoS of best-effort service,which leads to an undesirable service differentiation.On the basis,we apply the dynamical priority for the best-effort service to reduce delay and simulate to receive our results.更多还原