Utilizing LoRa for Control Link in Software-defined Aerial Networks: Analysis and Implementation

Software Defined Aerial Networks require longrange and reliable control links to carry out their missions/tasks especially when deployed in the vast areas. Unfortunately, existing control links provide services mainly tailored for controlling/monitoring the UAV flights and fall back to Wi-Fi for data transmission, which, on one hand drastically limits the effective mission areas of aerial networks, and on the other, necessitates multi-hop WiFi links to carry data over long distances. In this paper, we propose LoRA-based control link, on which both OpenFlow and flight control messages are carried in LoRa frames. This proposed link opportunistically tunes required spreading factor to ensure robust connectivity as the mission area grows. To this end, we build proof-of-concept drone using COTS hardware and open-source software, showcasing both network control and flight control data can be seamlessly transmitted over LoRA channels. Furthermore, we validate feasibility of our method for large-scale setup by extensive OMNET ++ simulations where we observe that Software Defined Aerial Networks can operate up to 3000m range and can successfully admit new network flows and update flight paths with only %3 percent packet drop rate.