RAN Design Guidelines for Energy Efficient 5G Mobile Xhaul Networks

5G mobile networks are currently being deployed leading to a wide range of new opportunities for the mobile network users. This work evaluates the energy consumption in the xhaul segment of the mobile network when expanding to 5G. The mobile xhaul network divides the traditional base station functions into a threefold architecture connected by a fronthaul, midhaul and backhaul network, which together form the xhaul network. This work contributes to Radio Access Networks (RAN) design and planning by combining classical aspects for increasing capacity in a RAN with an energy consumption analysis of the xhaul network. A mathematical model is used to investigate the network behavior when looking into different levels of bandwidth, spectral efficiency and number of cells. Results show that when reaching 5G capacity levels, even though the same capacity is achieved, the fronthaul will carry four times the amount of traffic compared to the midhaul. This work provides recommendations for a more energy efficient xhaul network architecture. Focus points include; identifying the most optimal number of cells, prioritize longer midhaul transport spans over fronthaul, and when possible increase capacity by bandwidth and spectral efficiency.