Empirical Indoor Signal Propagation of LoRa Link for IoT Applications

Internet of Things (IoT) based applications have grown rapidly for a variety of uses for electronically embedded device frameworks to provide data exchange and correspondence information. Crucial factors must be determined for various associated communication networks to support the practicality of IoT applications. Feasibility in long-range wide area networks and offering low power consumption wireless technology networks are the factors that are highly considered. Long Range (LoRa) modulation technique is the most promising communication technology to support IoT applications. The paper aims to highlight the best signal coverage of LoRa links in indoor propagation for integrated and efficient IoT applications. This measurement was performed in the hallway of the concrete dormitory building at UniKL BMI, Selangor, Malaysia. Measurements were performed between two TTGO-ESP32 LoRa boards equipped with LoRa module SX1276 923 MHz transceiver chip by Semtech. Each experiment was performed by a mobile transmitter and a fixed receiver which tested in four different antenna gains of 2, 3, 5 and 12 dBi. The measured data validates that LoRa networks can be used in indoor environments for IoT applications. Signal coverage is influenced by transmitter distance factors, antenna gain selection and signal propagation effects in the indoor environment.