WLANs give access to same services as those offered by the wired networks. They are easily deployed and require less investment. However, the medium must be shared between the stations in an equitable way knowing that it is of limited capacity, from where a degradation of performances. A new approach for the support of QoS is proposed. Its purpose is the improvement of the medium management. It is based on medium access control (MAC) enhancements, taking into account information from both the physical and the network layers for packets differentiation scheduling at the MAC level of one station. A simulation study shows the interest of introducing priority at MAC level in order to support QoS. For further information, please visit this web site.