enhance the IEEE 802.11 MAC protocol to support service differentiation. For this various proposed schemes include assigning different inter-frame spaces (IFS), scaling the backoff contention window and assigning different frame sizes according to the traffic priorities. A ravenous problem will impact on the transmission rate for lower priority traffic since much traffic with higher priority is transmitted. Thus the scheme to provide QoS aware MAC protocol should firstly supports fairness to both real time traffic having high priority and non real time traffic having low priority. Secondly, since the demands of such applications are increasing the load on the network so scheme should also consider network congestions. In this paper the comparative analysis of such schemes are considered which provides either fairness or avoid network congestions or both.\\n\\n