Improved E-model for monitoring quality of multi-party VoIP communications

Abstract

Abstract-Maintaining good Quality-of-Experience (QoE) is crucial for Voice-over-IP (VoIP) applications, particularly those operating across the public Internet. Accurate online estimation of QoE as perceived by end users allows VoIP applications take steps to improve QoE when it falls below acceptable levels. ITU-T recommendation G.107 introduced the E-model, which provides a means to assess QoE levels for two-party VoIP sessions. In this paper we provide an analysis of the accuracy of the E-model for multi-party VoIP sessions when all audio is processed by a centralised focus node. We analyse the impact of what we term the "Focus Transcoding Effect (FTE)," the "Focus Forwarding Effect (FFE)," and the number of end-points participating in the session. Through comparison to QoE metrics produced by the offline PESQ method for three common audio codecs, we show that the standard E-model does not provide accurate QoE assessment for multi-party VoIP sessions. We then introduce an improved Emodel for these codecs for multi-party VoIP sessions. We describe the implementation of the improved E-model in a QoE monitoring application, showing that it produces results similar to actual PESQ scores.

Quality of Experience in Telemeetings and Videoconferencing: A Comprehensive Survey

“…Table 8 gives an exemplary overview of QoE prediction models that are relevant for telemeetings. To the best of the authors' knowledge, those models have not been validated yet for different types of telemeetings and in particular not for multiparty settings, with the exception of Adel et al [329], who investigated the performance of ITU-T Rec. G.107, the E-Model, [115] for codec tandems that occur in central-bridge-based telemeeting systems.…”

SDN-driven multicast streams with adaptive bitrates for VoIP conferences

“…Hoeldtke and Raake defined in 2011 a new state model for MVoIP calls and applied statistical measures to recordings made during a three-party conferencing quality test, which was designed to evaluate the perceived quality under various speech transmission properties [7]. In 2013, Adel et al showed that the G.107 E-model is inaccurate in measuring the QoE of MVoIP calls and thus they proposed an improved E-model specifically designed for MVoIP sessions, which produces results very similar to the PESQ scores [8].…”