Abstract
The growth in mobile communications has resulted in a significant increase in energy consumption and carbon emissions, which could have serious economic and environmental implications. Consequently, energy consumption has become a key criterion for the design of future mobile communication systems. Device-to-device (D2D) communication has been shown to improve the spectral efficiency and also reduce the power consumption of mobile communication networks. In this paper, we propose a two-tier deployment of D2D communication within a network to reduce the overall power consumption of the network and compared it with full small-cell deployment throughout the network. In this context, we computed the backhaul power consumption of each link in the networks and derived the backhaul energy efficiency expression of the networks. Simulation results show that our proposed network deployment outperforms the network with full small-cell deployment in terms of backhaul power consumption, backhaul energy-efficiency, total power consumption of the tier 2 users and downlink power consumption, thus providing a greener alternative to small-cell deployment.