Combined link adaptation and traffic control scheme for MGS H.264/AVC video transmission
In this paper, we propose a joint link-adaptation and traffic control algorithm that efficiently allocates network resources to support multiple scalable video users over a capacity constrained wireless channel. Multi-rate networks, such as IEEE 802.16 or IEEE 802.11 use a link adaptation mechanism in the physical layer (PHY) and adjust the coding and modulation schemes to maintain the reliability of transmission under varying channel conditions. We consider Medium Grain Scalable (MGS) H.264/AVC video and employ a traffic control module that selectively drops individual video packets based on the packet dependencies in MGS. We present a framework that jointly optimizes the operation of the link adaptation and packet drop modules to achieve the highest video quality, while satisfying bandwidth/capacity constraints. Performance evaluations show that our proposed framework results in significant gains over existing schemes in terms of average video PSNR that can reach 3dB in some cases for different channel SNRs and different bandwidth budgets.