Maximizing QoE of Interactive Services with Audio-Video Transmission over Bandwidth Guaranteed IP Networks

This paper identifies factors affecting QoE (quality of experience) of interactive audiovisual communications over bandwidth guaranteed IP networks and finds how to maximize QoE in that environment. Among the factors, we focus on the guaranteed bandwidth between the terminals, video encoding bit rate, the playout buffering time, and task. Under the condition that the guaranteed bandwidth for video is kept constant for a given amount of the guaranteed bandwidth for audio, we made experiment on QoE assessment for various values of the video encoding bit rate and playout buffering time. We suppose two kinds of task: one is audio-dominant, while the other is a task whose video affects QoE more than the former. As a result of the experiment, we see that an appropriate selection of the pair of the video encoding bit rate and playout buffering time maximizes QoE for the guaranteed bandwidth for video. Furthermore, we notice that the playout buffering time should be carefully chosen especially for the latter task.