On the trade-off between quality of experience and energy efficiency in a heterogeneous cellular network

Official URL: http://risc01.sabanciuniv.edu/record=b1620287 (Table of Contents)

Two important issues in the current mobile cellular networks are: Firstly, the traffic on the internet has shifted from the file downloads to the video and audio streaming, secondly, the energy efficiency of cellular networks is a major concern. Particularly, the ever-increasing number of users with the exponential growth of high-data-rate traffic demand creates new challenges for wireless access providers. On the one hand, service providers want to satisfy the growing mobile data traffic demands but on the other hand, they try to reduce the operational costs and carbon emissions by decreasing the energy consumption. In this work, we explicitly quantify the tradeoff between quality of experience (QoE) and energy efficiency in a heterogeneous cellular network. We investigate an optimal resource on-off switching framework that minimizes the energy consumption of a heterogeneous cellular network while satisfying a desired level of quality of user experience. Considering an ON/OFF bursty arrival process, we introduce recursive equations to obtain the buffer starvation probability, as a QoE metric, of a mobile device (MD) for streaming services. The MD is in the coverage area of a femtocell base station (FBS) which is implemented at the cell edge of a macrocell base station (MBS). The buffer starvation event occurs whenever the mobile device’s buffer gets empty, and after each such event, the media player of the MD restarts the service after a certain amount of packets are prefetched (start-up or initial buffering delay). Our results have the potential to reduce carbon emissions of cellular networks by reducing the energy consumption throughout the network, while guaranteeing a target starvation probability to mobile users.