A Cross-Layer Based Rate Control Scheme for MPEG-4 Video Transmission by Using Efficient Bandwidth Estimation in IEEE 802.11e

Raising the quality of the streaming service in wireless networks has been the focus of intensive research over the years. Instable wireless channel conditions cause frequent transmission delays and packet losses due to fading and interference. Therefore, this situation leads to the degraded quality of video streaming service. The IEEE 802.11 Working Group is currently working on a new standard called IEEE 802.11e to support quality of service in WLANs. Several schemes have been proposed in order to guarantee QoS; however, they are not adaptable to network conditions. Accordingly, they suffered video quality degradation due to buffer overflow or packet loss. In this paper, to raise the quality of video streaming service in WLANs, we propose a cross-layer architecture. Our cross-layer architecture provides a differentiated transmission mechanism for IEEE 802.11e EDCA based on the priority of MPEG-4 video frames and the mechanism adaptively controls the transmission rate by dropping the frames based on efficient bandwidth estimation. Through simulations, the proposed scheme is shown to be able to improve end-to-end quality for video streaming service in WLANs.