Two-dimensional scaling techniques for adaptive, rate-based transmission control of live audio and video streams

One of the major obstacles facing designers of video conferencing systems is the problem of ameliorating the effects of congestion on interconnected packet-switched networks that do not support real-time communication. We present a framework for transmission control that describes the current network environment as a set of sustainable bit and packet transmission-rate combinations and show that adaptively scaling both the bit and packet-rate of the audio and video streams can reduce the impact of congestion. We empirically demonstrate the validity of adapting both packet and bit-rate using a simple feedback mechanism and simple adaptation heuristics to deliver audio and video streams suitable for low-latency, high-fidelity playout.