Influence of human body movement on mm wave communication in bullet train cars

Abstract

This paper examines the influence of the human body on the radio propagation characteristics of 60-GHz band mmWave (millimeter wave) communication systems in terms of the RSSI in the passenger car of bullet trains. We simulated the propagation characteristics of the 60-GHz band by a ray tracing method and investigated how many mmWave access points are necessary to meet the desired throughput at all the seats in the passenger car under the scenario that passengers enjoy the mmWave service while sitting in their seats. However, under scenarios such as a conductor or several passengers walking along the aisle from end to end through the passenger car, the propagation of mmWave is easily mitigated by obstructions such as the human body. So it is also important to further investigate to what extent human body movement along the aisle affects the RSSI of the STAs of those passengers sitting in their own seats. This paper first establishes a 3D simulation model of an ordinary passenger car and a 3D model of the human body. The simulation results numerically show the effect of human body movement and that the negative effect of human body movement can be absorbed if the mmWave APs are suitably allocated.