With the explosive deployment of wireless LAN technology in the past few years and increasing demand on multimedia applications, the efficient utilization of the precious wireless radio link resources and support of Quality of Service (QoS) in WLANs has become a prominent research issue. In this thesis, an adaptive p-persistent based I 802.11 MAC scheme in WLANs has been proposed. The proposed scheme can maximize the total channel throughput, and also provide service differentiation among multiple traffic classes. This is achieved by updating the transmission probabilities for the stations that compete for transmissions in a WLAN, adaptively based on the real time network measurements. Extensive simulation experiments in ns-2 demonstrate that the proposed scheme is capable of achieving the system throughput bound and the target throughout ratios among different traffic stations in a dynamic WLAN environment. Also, the low computational complexity makes the proposed scheme a suitable choice for real-time implementation.