A 'GAP-Model' based Framework for Online WoIP QoE Measurement

摘要

Increased access to broadband networks has led to a fast-growing demand for voice and video over IP (WoIP) applications such as Internet telephony (VoIP), videoconferencing, and IP television (IPTV). For pro-active troubleshooting of WoIP performance bottlenecks that manifest to end-users as performance impairments such as video frame freezing and voice dropouts, network operators cannot rely on actual end-users to report their subjective quality of experience (QoE). Hence, automated and objective techniques that provide real-time or online WoIP QoE estimates are vital. Objective techniques developed to-date estimate WoIP QoE by performing frame-to-frame peak-signal-to-noise ratio (PSNR) comparisons of the original video sequence and the reconstructed video sequence obtained from the sender-side and receiver-side, respectively. Since processing such video sequences is time consuming and computationally intensive, existing objective techniques cannot provide online WoIP QoE. In this paper, we present a novel framework that can provide online estimates of WoIP QoE on network paths without end-user involvement and without requiring any video sequences. The framework features the "GAP-model", which is an offline model of QoE expressed as a function of measurable network factors such as bandwidth, delay, jitter, and loss. Using the GAP-model, our online framework can produce WoIP QoE estimates in terms of "Good", "Acceptable", or "Poor" (GAP) grades of perceptual quality solely from the online measured network conditions.