Energy Consumption Model for Full-Duplex LoRa Backscatter-Based Sensor Node

Abstract

The integration of Wireless Sensor Networks (WSNs) into Internet of Things (IoT) brings new challenges in terms of range and energy consumption. Specifically, energy consumption is of great importance for future IoT sensors. Therefore, a thorough study must be performed to understand and evaluate the impact of different parameters that affect sensor node energy consumption. However, LoRa backscatter has been seen as a promising technology for long-range low-power IoT applications. Hence, this paper addresses the modeling of the energy consumption of a LoRa backscatter-based sensor node. We first derive the energy model for single-node communication and extend it to multiple-sensor-node communication where several sensors concurrently transmit their information. Furthermore, we derive an energy model for a battery-free sensor node that relies on the energy harvested from ambient sources to drive its operation. The simulation results show that both the LoRa parameters (such as payload size), the number of nodes in the network, and the number of retransmissions can impact the total energy consumption of the sensor node. Additionally, a single node powered by a battery with a capacity of 225 mAh and a transmission of 20 bytes every 5 minutes has a lifetime of about 14 years.