Perceptual-based playout mechanisms for multi-stream voice over IP networks

Packet loss and delay are two essential problems to real-time voice transmission over IP networks. In the proposed system, multiple descriptions of the speech are transmitted to take advantage of largely uncorrelated delay and loss characteristics on different network paths. Adaptive playout scheduling of multiple voice streams is formulated as an optimization problem leading to a better delay-loss tradeoff. Also proposed is a perceptually motivated optimization criterion based on a simplified version of the ITU-T E-model. Experimental results show that the proposed multi-stream playout algorithm improves the delay-loss tradeoff as well as speech reconstruction quality.