Energy-Aware Aware Cooperative Traffic Offloading via Device Device-to-Device Device Cooperations An Analytical Approach
Abstract: In this paper, we investigate the cooperative traffic offloading among mobiles devices (MDs) which are interested in receiving a common content from a cellular base station (BS). For offloading traffic, the BS first sends the content to some selected MDs which hich then broadcast the received data to the other MDs, such that each MD can receive the entire content simultaneously. Due to each MD's limited transmit-power power and energy budget, the transmission rate of the content should be properly designed, since it sstrongly trongly influences whether and how long each MD can perform relaying. Therefore, different from most existing MDs cooperative schemes, we focus on a novel joint optimization of the content transmission rate and each MD's relay-duration, duration, with the objective of minimizing the system cost accounting for the energy consumption and the cellular cellular-link link usage. To tackle with the technical challenge due to the coupling effect between the content transmission rate and each MD's relay relay-duration, duration, we exploit the decomposable decomposab property of the joint optimization problem, based on which we characterize different possible cases for achieving the optimal solution. We then derive the optimal solution for each case analytically, and further propose an efficient algorithm for findingg the globally optimal solution of the original joint optimization problem. Numerical results are provided to validate the proposed algorithm (including its accuracy and computational efficiency) and demonstrate