Characteristic Analysis and Modeling of Underground Space Wireless Communication Channels

Underground space is relative to above-ground space, mainly including underground shopping malls, underground parking lots, underground mines, etc. This paper focuses on the characteristics of wireless transmission in underground mines. In this paper, a new hybrid multimode waveguide model is proposed. Considering the movement of the receiving antenna, the proposed model combines the roughness loss and tilt loss of walls, and provides an analytical expression for the received power at any position in a tunnel. Using the proposed model, various tunnel factors are analyzed, such as the operating frequency, the cross section size, etc. It is found that, in underground mine, the curve of signal power can be divided into near field and far field. The operating frequency and the cross section size can affect the received signal power significantly. For different transmitting antenna positions, the same change of the receiving antenna position has different effects. The dielectric constant has little effect on received signal power.