Opinion model for estimating conversational quality of VoIP

VoIP (voice over IP) is one of the key technologies for recent telecommunication services. Since IP networks do not generally guarantee the transmission quality, it is extremely important to design and manage the QoS (quality of service) properly. To do this, it is indispensable to develop a systematic method which estimates subjective quality based on the physical characteristics of the VoIP system. The paper investigates the performance of the existing opinion model called E-model, and proposes a method to improve it. The experimental results show that the proposed model surely improves the estimation accuracy in evaluating practical VoIP systems.