TheWorld is not flat: Wireless communications in 3D environments

Wireless network deployments are becoming increasingly complex in order to cope with the exponential growth in mobile data traffic. Multi-tier technologies capable of supporting spatially dense networks enable high data rates, but require timely and accurate models of the radio environment, particularly for scenarios that incorporate dynamic access to spectrum. However, network planners, algorithm designers, and policy makers are often forced to rely on a small set of radio propagation scenarios, often assuming fixed receiver antenna heights (RAHs). In this paper we show that the RAH in fact plays a key role not only in terms of reception quality but also in determining the interference originating from other transmitters. Our extensive simulation studies show a large variability in key performance metrics of realistic wireless network topologies as RAH is varied, which are not captured through the current practice of selecting few effectively two-dimensional scenarios and drawing general conclusions from them. These results underline the importance of adopting more realistic assumptions on RAH for design, assessment, and policy making for wireless communication systems, and the need for new propagation models valid for a wider range of RAH values than models currently in use.