Energy-aware Multi-RAT Multicast Video Delivery

Delivering massive video content while consuming low energy at the user devices is an issue of increasing importance, both for the users and operators. In this paper we consider the problem of minimum-energy video delivery when the users are served by LTE multicast transmissions which are assisted by Wi-Fi networks. We formulate the optimization problem where we jointly decide the user association and spectrum allocation to multicast groups, and the Wi-Fi access point (AP) association and airtime allocation to users, in order to deliver a requested video quality. The problem is NP-hard and we propose a cutting planes algorithm, based on Benders decomposition, to expedite its exact solution. We evaluate our proposal using a wealth of simulation experiments based on 3GPP parameters and measurement studies. Our findings show that coordinated decisions on both networks reduce the devices power consumption by up to approximately 50%.