1 Introduction
Using unmanned aerial vehicles (UAVs) for delivery of various kinds of goods is becoming an increasingly popular approach. Although this promises advantages (e.g. saving time or resources), only a few commercial applications have been established so far. The reasons for this are, legal restrictions, as well as, the lack of technical implementations. Overcoming these obstacles is the goal of the project KIMoNo, which focuses on the mobility optimization in medicine to improve the quality and efficiency of the medical care for patients in rural and remote areas. Therefore, inter-modal transport concepts, including vertical take-off and landing (VTOL) drones, are researched. This includes the transport of (time-)critical medical goods and samples. As one aspect of this delivery system, an information exchange between the drone and authorized third parties must be established (e.g. to set landing / drop-off locations). This is achieved with a web-based information system, which can be accessed via mobile internet (4G/5G). However, the system shall also be suitable for very remote application scenarios (such as rescue operations in mountainous areas), where lack of cellular network coverage can’t be ruled out. Therefore, a fallback communication system is required to ensure a reliable communication between the unmanned aerial system (UAS) and a field team (e.g. mountain res-cue service) on the ground. This system must not interfere with the drone’s other communication systems. It has to be lightweight and energy efficient, in order not to limit the payload capacity or range of the UAV. A concept for the fallback communication system is proposed in this paper.