Abstract:We consider a LoRa sensor network featuring a UAV-mounted gateway for collecting sensor data (messages). Wake-up radios (WuR) are employed to inform the sensors of the UAV's arrival. Building on an existing random access scheme for such setups, we propose and evaluate two redundancy transmission protocols for enhancing the reliability of the data transfer. One protocol employs fountain-coded transmissions, whereas the other performs message replication. Our results illustrate how redundancy transmission can be beneficial under the time constraints imposed by the UAV's limited hovering duration, and how node density, hovering time, and sensor energy budget impact the performance of the schemes.
Abstract:We present a transmission scheme aimed at integrating wake-up radios (WuR) into LoRa sensor networks featuring UAV-mounted gateways. The sensors are informed of the UAV's arrival with the help of WuR, followed by sensor-to-UAV data transfer with frequency and spreading-factor hopping. The proposed scheme provides significant energy savings at the sensors while maintaining similar reliability levels compared to a scheme in which Class B LoRa beacons are used to perfectly synchronize the sensors with the UAV's data-collection window.