Role of UAVs and HAPS for IoT-based monitoring in emergency scenarios

Emergency communication scenarios require telecommunication systems to reach remote areas without ground connectivity. In this context, an aerial multi-layer system provided by Unmanned Aerial Vehicles (UAVs) and High-Altitude Platform Stations (HAPS) can support ad hoc coverage and assure backhaul connectivity. This paper surveys the role of UAVs and HAPS in emergency scenarios with particular reference to IoT applications (Internet of Emergency Service, IoES). We investigate NB-IoT and LoRa/LoRaWAN as today's major alternatives for IoES. Finally, an analytical approach is provided to compare the random-access schemes of these radio technologies, considering efficient access as a key for collecting ground IoT data in the emergency context.