Tracking of Rescue Workers in Harsh Indoor and Outdoor Environments

Making use of reliable and precise location and tracking systems is essential to save firefighters lives during fire operations and to speed up the rescue intervention. The issue is that Global Navigation Satellite System (GNSS) (e.g., GPS and Galileo) is not always available especially in harsh wireless environments such as inside buildings and in dense forests. This is why GNSS technology needs to be combined with auxiliary sensors like inertial measurement units (IMU) and ultra-wideband (UWB) radios for ranging to enhance the availability and the accuracy of the positioning system. In this paper, we report our work in the scope of the AIOSAT (Autonomous Indoor/Outdoor Safety Tracking System) project, funded under the EU H2020 framework. In this project, the Royal Military Academy (RMA) is responsible for developing a solution to measure inter-distances between firefighters, based on IEEE Std 802.15.4 compliant UWB radios. For these inter-distance measurements, accuracy better than 50 cm is obtained with high availability and robustness. Medium access control based on time division multiple access (TDMA) mechanism is also implemented to solve the conflict to access the UWB channel. As a result, each node in a network can perform range measurements to its neighbors in less than 84 ms. In addition, in this project, we are in charge of developing a long-range narrow-band communication solution based on LoRa and Nb-IoT to report updated positions to the brigade leader and the command center.