Research on the Effect of Refuge Hole on Radio Wave Coverage in Tunnels Using FDTD Method

In this paper, Finite Difference Time Domain (FDTD) method is used to analyze the effect of refuge holes on the radio wave coverage in tunnels. Different cases of single or double refuge holes located at various positions in the tunnel are analyzed to determine their impact on the received power. The influence of refuge hole shape on radio wave coverage along the tunnel is also studied. Simulation results demonstrate that the received power in the tunnel with refuge holes is different from that in the tunnel without holes, and shows a faster fluctuation. Moreover, the distribution of the fast fading points also varies with specific hole arrangements.