Feasibility of Alarm Events upon Smart Metering in LoRa Networks

Internet of Things (IoT) is pushing the Internet to the next level, bringing the number of connected devices to an unprecedented amount, creating new services and improving old services like the metering system. The advanced meter infrastructure (AMI) measures, collects and analyzes the distribution and consumption of utilities such as water, electricity, and gas, which are of vital importance for the implementation of smart cities. In this paper, we employ LoRa, which is a low power wide area network technology (LPWAN), for the communication of meter devices and network server, and we study the coexistence of two kinds of messages: regular and alarm events. Our focus is on the analysis of the alarm events, which can be characterized by emergency situations and require ultra-reliability. We investigated the feasibility of the alarms for a smart metering scenario through simulation campaigns and a mathematical model. By assigning a different spreading factor (SF) to the device depending on whether the event is regular or alarm, we assessed the system performance. We evaluate the availability, reliability, and quantity of alarms that satisfy the restricted requirements of alarms events and do not compromise the performance of regular events. The best performance for regular events at SF-7 was obtained when alarm events are allocated to SF-8, whereas the other combinations are affected for a stronger interference.