Wave Propagation Modeling Techniques in Tunnel Environments: A Survey

Abstract

The prediction of radio signal transmission in tunnels is important for wireless communication link design as it enables the delivery of optimum power to the intended receiver inside the tunnel. Several techniques have been proposed to estimate path loss for wireless communication inside tunnels. The radio coverage range and where base stations need to be installed can be figured out with the help of propagation models. At the time of developing these models, modeling complexity and environmental attributes, such as the tunnel geometry and the electrical and magnetic properties of its walls and interior materials are considered. A limited amount of literature currently overviews how waves transmits through tunnels and how electromagnetic wave transmission has recently changed. This survey, which examines current advancements in the propagation of waves in tunnels, aims to address this gap. In this review, thirty wave propagation models were analyzed and grouped into distinct categories for the first time. The detailed specifications of each model were omitted to make the survey easy to comprehend. This comparative research will help service providers adopt an appropriate propagation model and plan efficient transmitter and receiver placement and link management for a specific tunnel environment.INDEX TERMS Artificial neural network, radio wave propagation, ray tracing, scaling, tunnel.

Analysis and 3D Imaging of Multidimensional Complex THz Fields and 3D Diagnostics Using 3D Visualization via Light Field

“…The WDF allows the field to be represented as a set of GO rays when diffraction is considered. It can be seen that the EM field transmission by the GO rays leads to excellent results for frequencies 10 and 100 times lower [20] (also published as GJM [21]), which are known to have significantly higher diffraction than in this study. In addition, this experimental study shows that it is possible to reduce the scale and work with a small model of the tunnels.…”

“…This is because the energetic distribution of the Ey beam is uneven on the aperture, consisting of four peaks. It can be concluded that the dominant mode at the resonant frequency is mode TE 21 .…”

Numerical and Experimental Anaysis of Massive MIMO Channel Characteristics in a Rectangular Highway Tunnel at 5.9 GHz

“…Let us mention that this concept of CMD was also applied to study the stationarity of the scatterer contributions in wideband car-to-car channels, [16]. The coefficient characterizing the distance between the two correlation matrices R(z) and R(z+dz) calculated from the H transfer matrix, is defined as : (1) where f is the Froebenius norm.…”

“…Wireless communications in confined areas, as in road and railway tunnels have already been widely studied and a survey examining current advancements for modeling the propagation of waves in tunnels is presented in [1]. The frequency band under consideration often extends from about 1 GHz up to mm waves but, for road tunnels, special emphasis is placed on the 5.9 GHz band which is the allocated band in Europe dedicated to intelligent transport systems (ITS).…”

Comparative analysis of finite‐difference and split‐step based parabolic equation methods for tunnel propagation modelling

“…Radio wave propagation in tunnels has been extensively studied over decades [1][2][3][4][5][6]. With the emergence of new wireless communication systems such as communication-based traincontrol (CBTC) systems and 5G/6G wireless systems [7][8][9], there has been an increasing interest in radio wave propagation studies, as the development and deployment of those emerging systems rely on the prior knowledge of the propagation characteristics in the given railway environment.…”