  To meet increasing data demands, service providers are considering the use of
Unmanned aerial vehicles (UAVs) for delivering connectivity as aerial base
stations (BSs). UAVs are especially important to provide connectivity in case
of disasters and accidents which may cripple completely the existing
terrestrial networks. However, in order to maintain the communication of UAVs
with the core network, it is essential to provide them with wireless backhaul
connection to terrestrial BSs. In this work, we use stochastic geometry to
study the impact of millimeter-wave (mmWave) backhauling of UAVs in a hybrid
aerial-terrestrial cellular network where the UAVs are added to assist
terrestrial BSs in delivering reliable service to users (UEs). In the proposed
model, the UE can associate to either a terrestrial BS or a UAV connected to a
BS to get backhaul support. The performance of the proposed model is evaluated
in terms of coverage probability and validated against intensive simulations.
The obtained results unveil that the quality of the UAVs' mmWave backhaul link
has a significant impact on the UE 's experience and the deployment of UAVs
must be adjusted accordingly.
