Indoor-Outdoor of Wireless Link Propagation from tunnels and long corridors

Radio waves propagating in tunnels and long corridors have received attention in recent years. The indoor propagation inside a tunnel as well as the radiated pattern out of it are studied analytically and experimentally. The wave propagation along a tunnel is analyzed using ray tracing approach, which is useful when the tunnel’s dimensions much exceed the wavelength of the transmitted signal. A multi-ray model was used to reveal non-dimensional parameters, allowing realization of downscaled experiments. The resulted power intensity radiated out of the tunnel exit is calculated using farfield diffraction analysis. Scaled experiments were set to demonstrate the effects of the indoor transmission on the outdoor diffraction pattern. It is shown that the experimental measurements fit the numerical model results.