IEEE 802.11 Wireless Local Area Networks (WLANs) are widely deployed nowadays. With traditional layered architecture, current WLAN adopts functional layer partitioning and aims at optimization in individual layers. However, in a highly dynamic and media sharing wireless environment, the capacity enhancement at physical layers may not necessarily benefit the overall system performance. Moreover, in a multiuser setting, throughput can be increased substantially if partial knowledge of the channel is known. In this paper, we address the issue of cross layer design in the proposed "Weighted Fair Scheduling based on Adaptive Rate Control" (WFS-ARC) framework, where the PHY layer knowledge is shared with the MAC/LLC layer. It can make good matching of instantaneous channel conditions of multiple users with resource allocation to each user.