Performance Evaluation of LoRa 915 MHz for IoT Communication System on Indonesian Railway Tracks with Environmental Factor Propagation Analysis

Propagation along railway crossings exhibits different propagation characteristics compared to the general environment, especially in Indonesia. The environmental conditions along the railway crossings vary, including straight tracks, track turns, track bridges, and tunnel tracks, resulting in pathloss that originates from the material structure of the railroad tracks. The purpose of this research is to determine the path loss coefficient values (n) under railway crossing conditions using LoRa system transmission performance with a sample area in Indonesia. The method involves measuring the RSSI (Signal Strength parameter indicator) values of LoRa nodes under various environmental conditions, including straight tracks, track turns, track bridges, and tunnel tracks. Based on the results and analysis, the value of n for RSSI under straight track conditions with no railway crossing was found to be 1.948, while it increased to 2.4929 when trains passed through. Under turn track conditions with no trains passing, the value of n was found to be 1.8646.