Aircraft In-Cabin Radio Channel Characterization: From Measurement to Model

An aircraft cabin can be considered as an unusual propagation environment due to the construction materials and interior furniture of the aircraft. In this paper, a measurement and modeling procedure is proposed to characterize radio propagation inside an aircraft. The proposed procedure is divided into three phases in order to characterize (1) the propagation direction; (2) the reflections from the cockpit and tail ends of the cabin; and (3) the reflections from the sidewalls of the cabin. The first phase of the proposed measurement procedure is conducted in an Airbus A321 aircraft for the 1.8 GHz frequency band. In the measurements, the receive antenna is located in 24 different passenger seats and three different transmit antenna locations are considered to investigate how the propagation characteristics change according to the propagation direction. According to the measured values, we found that the path loss exponent of the distance dependent path loss model (decay constant) differs according to the propagation direction and distance. The path loss exponent is found equal to 1.5 and 2.6 for both the propagation directions when the transmitter-receiver separation is shorter than 5 meters and longer than 14 meters, respectively. However, when the distances between 5 and 14 meters are considered, the path loss exponent is found equal to 2 for in- flight propagation direction and 2.3 for in-rear propagation direction. In light of the obtained radio propagation characteristics for the first phase of the proposed procedure, it is worthwhile to follow the remaining phases in order to improve channel propagation modeling inside an aircraft.