Scooter-to-X communications: Antenna placement, human body shadowing, and channel modeling

In countries such as Taiwan, with a high percentage of scooters, scooter-related accidents are responsible for most injuries and deaths of all traffic accidents. One viable approach to reduce the number of accidents is to utilize short-range wireless communications between the scooter and other vehicles. This would help neighboring vehicles to detect the scooter and vice versa, thus reducing the probability of a collision. In this paper, we perform extensive measurements to characterize communication links between a scooter and other vehicles. Our results suggest that when the line-of-sight propagation path is blocked by the body of the scooter driver (and possibly also a passenger), shadowing of the human body results in significant signal attenuation, ranging from 9 to 18 dB on average, presenting challenging channel characteristics unique to scooters. In addition, we perform simulations, which show that it is imperative to incorporate the body shadowing effect to obtain realistic simulation results. We also develop a model to determine whether human body shadowing is in effect, given the relative positions of the transmitter and the receiver.