  In this work, we propose an UAV-aided Integrated Access and Backhaul (IAB)
system design offering 5G connectivity to ground users. UAV is integrated with
a distributed unit (DU) acting as an aerial DU, which can provide 5G wireless
backhaul access to a terrestrial central unit (CU). The CU-DU interface fully
complies with the 3GPP defined F1 application protocol (F1AP). Such aerial DU
can be instantiated and configured dynamically, tailoring to the network
demands. The complete radio and access network solution is based on open-source
software from OpenAirInterface (OAI) and off-the-shelf commercial 5G mobile
terminals. Experimental results illustrate throughput gains and coverage
extension brought by the aerial DU.
