A practical model for ensemble estimation of QoS and QoE in VoIP services via fuzzy inference systems and fuzzy evidence theory

Nowadays, there is an increasing number of Voices over IP (VoIP) services offered in telecommunication networks with specific quality requirements. Such requirements impact upon both the objective quality of service (QoS) of the end-to end connection as well as the subjective quality of experience (QoE) as perceived by the end user. In this study, we have proposed an integrated QoS and QoE evaluation system based on the combination of fuzzy inference systems and fuzzy evidence theory. For quality criteria, we have used QoS as a technical source from the viewpoint of service provider and QoE as the end user approach in front of service. We have divided the positive and negative variables of QoE into two distinct systems. At the same time, a parameter has been proposed as quality, which is the total quality of a service according to the objective and subjective viewpoints. To calculate the parameters mentioned above, a fuzzy inference system has been utilized. In addition, to obtain all data sources as an evidence of quality, Dempster-Shafer evidence theory has been employed. Finally, the proposed approach evaluated through the quality of VoIP services in three real cases and the results are discussed.