Long-Term Monitoring of Smart City Assets via Internet of Things and Low-Power Wide-Area Networks

Abstract

This article discusses the design and testing of LoRa communication-based Internet-of-Things devices to track relatively small and inexpensive nonpowered assets, such as concrete roadway barriers within a smart city, highlighting how these requirements differ from those associated with larger and more expensive assets. More specifically, this article presents an innovative method to minimize LoRa module energy by monitoring for localized movement or acceleration as well as changes in the received signal strength from the base station. One important aspect of this method is normalizing received signal strength values to account for real-time changes in weather and temperature. This article also presents a method to optimally place LoRa relays while considering the needs of professionals working in the commercial, industrial, and construction settings. The authors' primary objective is to develop, implement, and test hardware with the ability to track these assets effectively while being inexpensive enough to warrant their placement on smaller assets, far reaching enough to track and communicate with assets over ranges up to 2.5 km, durable enough to withstand the stresses of commercial and construction sites, and sustainable enough to operate for 5+ years without manual intervention or an energy source to recharge the unit.