Five-Zone Propagation Model for Large-Size Vehicles Inside Tunnels

Abstract

Abstract-An accurate characterization of the wave propagation inside tunnels is of practical importance for the design of advanced communication systems. This paper presents a five-zone propagation model for large-size vehicles inside tunnels. Compared with existing models, the proposed model considers the influence of the large size of the vehicle, and covers all propagation mechanism zones and their dividing points. When a large-size vehicle is passing the transmitter, the received power suffers a deep fading as the direct wave is blocked by the vehicle itself. This zone is called the near shadowing zone. Then, when the vehicle has moved past the transmitter, the line of sight is recovered. If the vehicle is still close to the transmitter, the free space propagation zone starts. Then, as the distance increases, the vehicle enters the multi-mode propagation zone, where higher order modes are significant. Further away, when high order modes are greatly attenuated, guided propagation is stabilized. Finally, when the vehicle is extremely far from the transmitter, the waveguide effect vanishes because of the attenuation of reflected rays. Two sets of measurements are employed to validate the model. Results show good agreement, and therefore, the model presents an effective way to predict the propagation inside tunnels for large-size vehicles.

Measurement and Analysis of Extra Propagation Loss of Tunnel Curve

“…As the representatives of deterministic models, modal analysis based on waveguide theory [15], [16], models based on geometrical optics (GO) approach [17]- [19], and models based on numerical methods for solving Maxwell equations for tunnel environment, e.g., vector parabolic equation techniques [20], support an accurate way to predict the propagation characteristics in tunnels. On the other hand, empirical models, such as two-slope models [21], [22], three-slope model [23], [24], four-slope model [25], [26], and five-zone models [27], [28], etc., predict the propagation in tunnels in a fast and effective way. However, most of these models are sophisticated for the straight tunnels.…”

Complete Propagation Model Structure Inside Tunnels

“…It locates at the distance where the fundamental modes E h 11 (horizontally polarized E-field) and E v 11 (vertically polarized Efield) have suffered one reflection [16]. In an equivalent rectangular tunnel, the E h 11 mode is defined by the phase relations: sin φ V = λ 2W ; the E v 11 mode is defined by the phase relations: sin φ H = λ 2H , where φ V and φ H are the grazing angles of incidence of the rays with the vertical and horizontal walls, respectively.…”

“…X σ represents a log-normal distribution with standard deviation σ. N L max is the maximum near shadowing loss when there is no LOS between Tx and Rx, which is modeled by using the principle of least-squares curve fitting on the measured data in [13]. Details of modeling and parameters can be found in [13,16].…”

Modeling link quality for high-speed railway wireless networks based on hidden Markov chain

“…In cutting scenario, the small-scale fading characteristics were modeled at 2.35 GHz in [11,12] and at 930 Mhz in [13][14][15][16]. In [17], the wave propagation of railway tunnels were analyzed. In [18,19], the influence of crossing bridges and train stations were reported on propagation loss model.…”