Content-Aware Resource Allocation For Video Streaming Over Wireless Networks

The prospect of offering multimedia services to mobile clients over wireless networks becomes increasingly more viable. Assuming real-time video streaming to multiple users, the limited achievable data rates may not be sufficient to transmit every packet of every video frame to all the users while guaranteeing that all the packets needed to decode a frame of the video sequence are received at the decoder buffer prior to the playback time of that frame. Thus results in avoidably packets discarding. Therefore, it's key to adopt efficient resource allocation and packet scheduling schemes to make sure packet discarding have least influences on the reconstructed video quality at the receivers. Wireless video applications require appropriate scheduling techniques that make use of the specific characteristics of video content, as well as the well known gains from multi-user diversity.Aimed at this issue, a cross-layer packet scheduling scheme that streams pre-encoded video over wireless downlink packet access networks to multiple users is presented. The proposed scheme overcame the drawbacks of traditional packet scheduling algorithms which didn't consider the delay constraint of video streaming. The scheme makes use of a packet prioritization strategy that orders video packets based on their contribution to reducing the expected distortion of the received video sequence. Therefore, packets with major importance to reconstructed video sequences are transmitted first to minimize the distortion of the received video sequences. The proposed scheme is based on the thought of cross-layer optimization, which takes into account video encoding method, the channel conditions as well as the decoding and error-resilience methods employed at the decoder. A novel simulation system for wireless network transmission of H.264/AVC video stream is presented in this paper. It's efficient to simulate video transmission, evaluate reconstructed video and analyze performance of relative algorithms. The proposed content-aware resource allocation and packet scheduling algorithm over wireless network is simulated over the simulation system. Performance analysis is compared with the traditional content-independent scheduling algorithm, in terms of both objective PSNR and subjective video quality. Qualitatively research on the impacts of the H.264/AVC error resilience technology to is performed on the simulation system too. Reasonably utilizing the trade-offs between compress efficiency and error resilience is useful to improve the reconstructed video quality at the receivers.Simulation results show that the average PSNR of the reconstructed video at the receiver is improved about 0.5 to 1.2 dB while comparing the proposed content-aware scheme to the content-independent scheme. What's more, the content-aware scheme tends to provide similar, continuous quality across all the frames. It indicates content-aware resource allocation and packet scheduling scheme provides a viable method for downlink packet scheduling as it can outperform current content-independent techniques.