Developed as a simple and cost-effective wireless technology for reliable and portable services, IEEE802.11 has gained popularity at an unprecedented rate. However, due to lack of built in quality service support IEEE802.11experiences serious challenges in meeting multimedia and other services and applications. This paper discusses the IEEE802.11 quality of services with enhanced MAC layer. The IEEE802.11 for the WLAN standard focuses on the MAC and Physical layers for AP based networks and ad-hoc networks. The original standard supported three PHY standards: IR, FHSS and DSSS. Here the medium, access scheme which is called EDCF, and is adopted in an upcoming standard IEEE802.11e to allow medium access for applications with Qos requirements and is analyzed, described & discussed and its performance is also calculated with the help of OPNET simulator.