New TCP video streaming proxy design for last-hop wireless networks
TCP based HTTP video streaming is becoming more and more popular in recent years. However, for last-hop wireless access, due to TCP's additive increase/multiplicative decrease (AIMD) congest control mechanism, when interference and fading are strong, TCP streaming behaves poorly. In this research, we propose a new design of TCP video streaming proxy at the wireless base station. The new proxy's mission is two folds. First, it transparently isolates the wireless network from the wired network. Specifically, for the last-hop wireless transmission, it adopts a new variant of TCP, we call it raw-TCP, which in combination with a fair scheduler component in the proxy, results in an increased average throughput with low dynamics. Second, through video adaptation, i.e. priority guided packet reordering and deadline driven adaptive truncation, the proxy eliminates playback jitter while maintaining small visual quality variation between successive frames. These two functions fundamentally differentiate our research from the vanilla split-TCP schemes. In our research, the TCP proxy is a multimedia aware element while in traditional split-TCP, the relay node is multimedia oblivious. Simulation results using ns-2 verify the effectiveness of the proposed solution.