Comparison between UAV IoT solutions with and without satellite backhaul link

New applications related to the Internet of Things (IoT) concept are constantly growing and wide-spreading. Some of these applications are typically referring to urban environ- ments, such as the applications within Smart City and Smart Home scenarios, while others are mostly referring to rural environments, such as the applications within Smart Agriculture and Smart Grid scenarios. Focusing on rural environments, the use of Unmanned Aerial Vehicles (UAV) can help collect data from multiple IoT devices, such as sensors, which could be spread in a wide area and difficult to physically reach. However, forward these data to storage centers typically deployed on the Cloud or to the Edge of the network closer to the users may be a challenge due to the lack of any telecommunication infrastructure in rural and remote areas. In this paper, we consider two possible solutions both based on a UAV equipped as an IoT communication gateway. We consider the Long Range Wireless Area Network (LoRaWAN) protocol, belonging to the Low Power Wide Area Network (LPWAN) category, as the communication protocol of IoT devices. The considered scenario involves the use of the UAV to collect data generated by multiple IoT LoRaWAN sensors. The difference between the solutions is how these data reach the storage plat- form we assume is located on the Internet. In the first solution, the UAV is directly connected to a storage platform through a simulated satellite link; while in the second solution the UAV acts as a data mule, temporary storing the information onboard during all the data gathering phase downloading it to the storage platform only when it comes back to the landing spot. A performance analysis has been carried out comparing the two solutions in terms of delivery time, required storage space, and energy consumption.