Abstract: Robust streaming of video over 802.11 WLANs poses many challenges, including packets losses caused by network buffer overflow or link erasures, time-varying wireless channel and video content characteristics etc. To improve the performance of real-time video transmission over 802.11 WLANs, the use of cross layer design approach is required which allows communication between layers by permitting one layer to access the data of another layer, thereby facilitating the exchange of information. One of such design approach includes Application (APP) and Medium Access Control (MAC) layers considerations and is explored in this paper. This study focuses on H.264/MPEG4-AVC, the most widely accepted video coding standard and provides better quality compressed video and flexibility in compressing and transmitting video at APP layer and the retry limit settings of the MAC layer can be optimized in such a way that the overall packet losses are minimized. In this paper, the proposed Top-Down cross-layer design involves the mapping of H.264 video slices (packets) to appropriate access categories of IEEE 802.11e according to their information significance.