Delay Prediction for Real-Time Video Adaptive Transmisson over TCP

Abstract

Real-time multimedia streaming applications are increasingly using TCP instead of UCP as underlying transport protocol, however the great end-to-end delays are the major factor to influence the quality of streaming across the Internet using TCP. In this paper, we point the requirement for transmitting real-time video with acceptable playing performance via TCP and present a stochastic prediction model which can predict the sending-delays of video frames.  Based on the prediction model, we propose a real-time video adaptive transmission scheme which can dynamically adjust video frame rate and playout buffer size according to available network bandwidth. The scheme does not require any modifications to the network infrastructure or TCP protocol stack and only wants to measure some parameters including video frame size, loss ratio, congestion windows size, RTT and RTO time before video frames are sent. The performance of proposed prediction model and adaptive scheme are evaluated through extensive simulations using the NS-2 simulator.