A simulation-based methodology and tool for automating the modeling and analysis of voice-over-IP perceptual quality

A simulation-based methodology is developed for analyzing the perceptual quality of voice-over-IP calls as a function of network quality-of-service (QoS) parameters and choices in configuration and implementation. The proposed method combines the use of existing objective voice-quality measurement algorithms, such as the ITU-T P.861 PSQM and P.862 PESQ, and pre-recorded natural or artificial voice reference signals, such as the ITU-T P.50, with the discrete-event simulation of a network QoS model. A significant advantage of the method is that it does not involve the use of human subjects in evaluating subjective voice quality. This enables one to entirely automate the process of quantifying call quality as a function of network QoS and implementation choices such as packet size and codec type. Such automation enables one to realize significant time and cost savings in obtaining experimental results. A tool implementation is described that includes basic network packet loss, delay jitter, and call multiplexing models. Example numerical results are presented. The generalization of the method to the automated perceptual quality evaluation of audio, video, and multimedia signals is also described.