Low-altitude UAVs are frequently blocked by obstacles (or buildings) in urban networks. So, the link stability is as critical as coverage probability. In this paper, we analyze the dynamic connectivity of a UAV-to-Ground link using stochastic geometry. We model buildings as a marked homogeneous Poisson Point Process. Using this model, we obtain analytical expressions for the mean total connection time and the expected number of interruptions. We reveal a fundamental trade-off between improving connection time and interruptions. We provide the existence of an optimal flight altitude numerically, which balances the connectivity and stability of a UAV-to-ground link. 2018 The Korean Institute of Communications and Information Sciences. Publishing Services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ).
Jung et al. (Sun,) studied this question.