Uncertainty evaluation of speech quality measurement in VoIP systems

The paper analyses the problem of testing the speech quality performance provided by a real VoIP telephony network. To this aim, the objective measurement of end-to-end speech quality by means of the PESQ algorithm is discussed, and its accuracy as an estimator of the subjective Mean Opinion Score is summarised Then, the application of the PESQ algorithm in the analysis of the performance of real life VoIP systems is presented. A characterization of the PESQ algorithm uncertainty under different measurement conditions and network scenarios is provided. This particular problem, in fact, has received little attention in the literature, even though many results on the use of the PESQ algorithm in other types of applications have been presented by researchers. Experimental data obtained in the speech quality characterization of a real-life VoIP equipment (Media Gateway) are reported and discussed. © 2007 IEEE.