Speech quality of VoIP: bursty packet loss revisited

This paper presents a study on the influence of bursty packet loss on the listening quality of Voice over IP (VoIP) connections. The goal is to revisit this degradation type in the context of today's narrowband (NB) and wideband (WB) telephone connections as used in fixed-line VoIP and Voice over LTE (VoLTE), and to analyse the relation between listening test results and predictions by existing models. Packet loss patterns were generated using a 2-state Markov model. A listening test was carried out, and the results were analysed using analysis of variance (ANOVA) and Post-hoc tests indicating a dependency of quality on the bandwidth, the loss distribution and applied packet loss concealment (PLC). The results were compared with scores obtained from the standardized speech quality models POLQA (ITU-T Rec. P.863), PESQ (ITU-T Rec. P.862) and the E-model (ITU-T Rec. G.107). Implications on current approaches in VoIP quality monitoring are indicated.