Exploiting diversity of usage to enhance user equipment energy efficiency in LTE networks

Energy efficiency is widely recognized as an important factor for future cellular networks. For mobile devices, energy efficiency leads to extended battery life. Existing works consider battery to be equally important for all users at all time. We recognize that the value of a device’s battery depends on the user’s target usage. In particular, we introduce the notions of valueless and valued battery, as being the available battery when the user does or does not have access to a power source, respectively. We argue that user experience only depends on valued battery. We propose a cooperative system to help raise the overall amount of valued battery in the network. Our system makes use of device-to-device communications underlaying LTE to create cooperative relay links between users. Users who expect to have a large amount of valueless battery help relay traffic for users with a small amount of valued battery. We develop our system as a proximity service for future LTE releases. We propose a framework to study utility functions to evaluate the value of battery. We show that with appropriate utility functions, a set of thresholding cooperative rules ensure network performance improvement. We illustrate this improvement through simulation. Our simulator source code is made available to the public.