The IEEE 802.11 WLAN is primarily used for web browsing which belongs to the category of non-real time application. But the demand of real time applications like VOIP and video conferencing has become very much common to such WLAN. With IEEE 802.11e Mac protocol it is possible to improve the QoS for both real and non-real time traffic by service differentiation. To ensure efficient utilization of the radio resources and enhanced QoS the load imbalance should be resolved among APs from different BSSs. In large scale WLAN inter AP communication mechanism can be employed along side the current admission controller under EDCA. Beside service differentiation inter AP differentiation based QoS management can lead to efficient utilization of radio resources by moving STAs from heavily laded to a less loaded AP and ensure better QoS for all types of traffics. In this paper we propose a dynamic and fair AP selection mechanism to improve the QoS in a WLAN. The simulations have been carried out with NSv2.34.