In this study, throughput and delay performance of IEEE 802.11b and 802.11e is presented under non-saturation conditions. In order to improve the performance of IEEE 802.11b, the IEEE 802.11e has been proposed to improve the Quality of Services (QoS) for multimedia application. The standard 802.11b CSMA/CA contention mechanism does not support QoS but the standard 802.11e provides QoS by adjustment of MAC parameters. The comparison of 802.11b DCF and 802.11e EDCA mechanism by using Network Simulator (NS-2) with different parameters such as throughput, delay, CW_(min) and AIFS differentiation are simulated. The EDCA stations have more competitive advantages than 802.11b under all the above parameters. The simulation results show that the proposed algorithm improves the performance of the EDCA stations.