Green Video Delivery in LTE-based Heterogeneous Cellular Networks

In this paper we present an optimization framework that formalizes the inherent trade-off between the user perceived quality of wireless video, and the energy consumption cost of the network. The former is formulated in the context of the emerging heterogeneous cellular networks (HCN) based on LTE. We also consider users that employ dynamic adaptive streaming over HTTP (DASH). Our framework quantifies this trade-off carefully, by delving into the details of DASH, the LTE network, and the HCN architecture. The result is a complex problem that is solved in two levels. The master problem is responsible for decisions regarding the the user association and the average power they are allocated. The solution of this problem also entails a decision about the encoding rate of the DASH video segments. The previous decision is used in order to perform resource allocation at a finer level by considering the technical details of LTE that allocates resource blocks and power simultaneously. Numerical results are presented with realistic parameters for the LTE network and the video traffic.