Modified IEEE 802.11 EDCF to Implement QoS of Multimedia Traffic

Enhanced distributed coordination function has been proposed in IEEE 802.11e draft to ensure QoS of multimedia traffic over WLAN. However the performance of EDCF may be poor in some cases. Thus, a modified EDCF, MEDCF is presented in this paper, which can supply different multiple access techniques to services with different requirements on QoS, such as p-persistent CSMA/CA for real-time service and non-persistent CSMA/CA for non-real-time service. Analysis and simulation show that MEDCF can support multimedia service and assure quality of real-time service.