Distortion-Delay Tradeoff in Real-Time Wireless Video Scheduling

Existing scheduling schemes for real-time wireless video services generally focus on system throughput or delay, and do not take into account the relationship between the transmission delay and video distortion. In this paper, we develop and evaluate a delay-distortion-aware wireless video scheduling scheme in the framework of cross-layer information adaptation. At first, we construct a general video distortion model according to the observed wireless network parameters, as well as each video sequence´s rate-distortion characteristic. Then, we exploit a distortion-aware wireless video scheduling scheme and derive a bound on the asymptotic decay rate of the video distortion. Furthermore, the relationship between the delay and distortion is studied by taking into account video application delay and distortion requirements for specific wireless network environments. The proposed scheme is applied to heuristically find optimal tradeoff between the delay and distortion. Extensive simulation results are provided to demonstrate the effectiveness and feasibility of the proposed scheme.