On the Uplink and Downlink EMF Exposure and Coverage in Dense Cellular Networks: A Stochastic Geometry Approach

Existing studies analyzing electromagnetic field (EMF) exposure in wireless networks have primarily considered downlink (DL) communications. In the uplink (UL), the EMF exposure caused by the user's smartphone is usually the only considered source of radiation, thereby ignoring contributions caused by other active neighboring devices. In addition, the network coverage and EMF exposure are typically analyzed independently for both the UL and DL, while a joint analysis would be necessary to fully understand the network performance. This paper aims at bridging the resulting gaps by presenting a comprehensive stochastic geometry framework including the above aspects. The proposed topology features base stations (BS) modeled via a homogeneous Poisson point process as well as a user process of type II (with users uniformly distributed in the Voronoi cell of each BS). In addition to the UL to DL exposure ratio, we derive joint probability metrics considering the UL and DL coverage and EMF exposure. These metrics are evaluated in two scenarios considering BS and/or user densifications. Our numerical results highlight the existence of optimal node densities maximizing these joint probabilities.