Efficient Indoor RSSI Analysis for IoT-Based Weather Stations Using LoRa Protocol in Agricultural Applications

Recently, LoRa (Long Range) wireless communication technology has gained prominence as a leading LPWAN (Low Power Wide Area Network) solution in various applications of IoT (Internet of Things). Leveraging Chirped Spread Spectrum (CSS) modulation, LoRa's bit rate per symbol is directly influenced by the spreading factor (SF), which ranges from 7 to 12. This study focuses on an indoor environment, where the RSSI (Received Signal Strength Indicator) parameter is thoroughly examined. Utilizing two HTCC AB01 LoRa transceivers, we assessed the impact of adjustable spreading factors SF9 and SF12 on RSSI performance. Our research operated within the 868 MHz frequency band and a 125 kHz bandwidth, systematically measuring RSSI in both line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios over short distances. Temperature data from a DHT22 sensor was transmitted to evaluate signal strength under varying conditions. The empirical results demonstrate the practical application of LoRa technology in indoor environments, emphasizing the significant influence of the spreading factor on RSSI performance. Additionally, the study highlights the increased signal power losses experienced under NLOS conditions compared to LOS scenarios..