Secure Energy Constrained LoRa Mesh Network

LoRa (Long Range) is a low-power wide-area network technology well-suited for Internet of Things (IoT) applications. In this paper, LoRa is used in a cattle monitoring application where an ad-hoc mesh network is configured to collect GPS and accelerometer data from cattle-worn sensors and relay the collected data to a base station. Free-range cattle monitoring is a challenging application since the battery-powered sensors must be small and energy efficient, and enable data communications over long distances from unpredictable locations. We propose novel changes to the existing LoRa mesh network protocols that minimize energy consumption by using global time synchronization enabled by GPS sensors and a concurrent transmission property unique to LoRa. The mesh routing phase efficiently occurs during every data collection period, making this approach ideal for networking highly mobile sensors. We integrate efficient authentication and encryption techniques in the data exchange operations to prevent spoofing and to provide confidentiality in the message exchanges between the sensors and the base station. The performance of the proposed secure implementation is compared to an equivalent insecure implementation. Multiple cattle distribution scenarios are constructed and compared to evaluate the energy consumption of the proposed scheme.