Empirical path-loss model in train car

In this study, path loss measurements were performed in a train environment at five frequencies used in present and future wireless communication technologies, considering various transmitter (Tx) - receiver (Rx) configurations. First, a one-slope path-loss model was constructed for each frequency. Path loss exponents below 1.5 at lower frequencies (~ 1 GHz) indicate a waveguide effect, while the influence of the seats on the propagation at higher frequencies (~ 2 GHz) results in exponents larger than 2. Finally, a single, frequency-dependent path-loss model was fitted to the total data pool, resulting in a model with a coefficient of determination, R², of 0.77.