Energy/Quality-of-Experience TradeOff of Power Saving Modes for Voice Over IP Services

Deploying a power saving mode (PSM) is considered an effective solution for saving energy; however, a key challenge is how to simultaneously save energy and support a required level of quality of experience (QoE) using PSM for voice over IP (VoIP) services. This paper aims at developing a novel Markovian-based evaluation framework that assesses the energy consumption and QoE, achieved by a fixed sleeping time-based PSM. Based on this framework, a novel QoE-aware PSM is developed, which exploits the ON-OFF characteristics of a VoIP session to further improve the energy saving, while accounting for the effect of bursty losses on the QoE. The QoE and energy consumption achieved by the proposed PSM are evaluated via solving a system of linear equations. This facilitates the analytical formulation of the QoE/energy tradeoff that is needed for the successful integration of this QoE-aware PSM within the traffic offloading mechanisms. Numerical results validate the accuracy of the performance evaluation framework and verify the efficacy of the proposed QoE-aware PSM in saving energy while assuring a desired level of QoE. The Pareto-optimal operational regime show that the proposed QoE-aware PSM significantly reduces power consumption at a desired level of QoE compared with its counterparts.