Path Loss Modeling for Air-to-Ground Channels in a Suburban Environment

In the context of intelligent transportation systems and smart cities, vehicle-to-vehicle communications will play a major role in providing localized information services. Unmanned aerial vehicles are an important part of this infrastructure, as they provide flexibility and enable demand-based (re)deployment of network nodes. However, these drone-based scenarios have unique propagation channel characteristics that are not yet fully explored. In this paper, we investigate channels measured between a ground base station and drone-mounted platform, emulating air-to-ground communications at different heights and for different propagation conditions. Using a log-distance path loss model, we obtain LoS path loss exponent values 6.3-8.4, increasing with height (12.1-49.2 m). Vegetation obstruction resulted in values 15.0 and 13.2, at 33 m and 49 m heights, respectively. Addition of an angle-dependent loss component improved the fit slightly in only two scenarios. Its new component exponent was statistically significant at a 5% significance level in only half of the cases.