On Caching and Base Station Densification Tradeoff for Maximized Energy Efficiency

In this paper, we study a two-tier cellular network with cache-enabled small base stations (SBSs). In our model, a SBS has the ability to coordinate with neighboring SBSs and fetch data from their caches. We focus on the effect of SBSs' density on the network's energy efficiency. To this end, stochastic geometry theory is used to model the SBSs and users distributions, which enables us to find closed-form expressions for the network's energy efficiency as a function of the SBSs density and the cache size at each SBS. The optimal SBSs density that maximizes the energy efficiency is characterized, and the relation between this optimal density and the cache size at the SBS is highlighted. Furthermore, the effect of the users' density in the network on the energy efficiency and the optimal SBS density is investigated 1 This work was supported in part by the Egyptian National Telecommunications Regulatory Authority (NTRA).. © 2018 IEEE.