Impact of urban environments on FANET communication: A comparative study of propagation models

Abstract

The steady rise in the use of unmanned aerial vehicles (UAVs) is leading to the development of an ever-growing number of applications. In urban settings, efforts like the U-Space initiative in Europe are striving to standardize and regulate the operations of UAVs. To support these applications and further UAV research, it is essential to thoroughly understand UAV communication, both among and between UAVs. Nonetheless, we have identified a lack of studies on communication models, especially in urban areas where obstacles like tall buildings can disrupt communication. This study offers a comprehensive review of current measurement campaigns on channel models for aerial communication. In addition, we conducted experiments on (i) the separation distance between two UAVs, (ii) Multi-UAV communication and (iii) Multi-UAV to ground communication using three different city profiles in Spain (Valencia, Barcelona, and Madrid). To accomplish this, we utilized an advanced co-simulation framework that accurately models both UAV mobility (Ardusim) and communication (OMNeT++). Our results regarding UAV-to-UAV communication in a city environment indicate that: (i) the communication range, in our specific experiments, is limited to around 400 meters. Afterward, the Packet Delivery Ratio (PDR) declines significantly. (ii) Different communication models yield similar results. (iii) UAV-to-UAV communication becomes feasible at higher altitudes (e.g., 120 m), particularly in the presence of tall buildings. With respect to the Multi-UAV to ground communications, we can conclude that again, the altitude of the UAVs is paramount. Furthermore, increasing the number of UAVs providing service to the ground does increase the PDR, but only ever so slightly.