Energy efficient small cell density optimization based on stochastic geometry in ultra-dense HetNets

To meet 1000x wireless traffic volume increment in the next decade, a larger number of small base stations (SBSs) have to be densely deployed for 5G cellular networks. Analyzing the optimal density of small base station from the perspective of energy efficiency is very meaningful for green 5G mobile networks. In this paper, we analyze the SBS density for energy efficiency in ultra-dense heterogeneous networks (HetNets) by means of the stochastic geometry theory. We first derive the expression of the whole networks energy efficiency. Then, the optimal SBS density is deduced by fixing the density of macro base station (MBS). Our study reveals that the optimal SBS density for network energy efficiency can be calculated with different user densities. Extensive simulation results verify the accuracy of our theoretical analysis.