Propagation Mechanism Analysis Before the Break Point Inside Tunnels

Guan, Ke; Zhang, Zhong; Ai, Bo; Briso-Rodríguez, César

doi:10.1109/vetecf.2011.6092867

Cited by 18 publications

(9 citation statements)

References 10 publications

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“…It is generally observed [17,32,33] that propagation can be divided into two regions: the near zone and far zone. The signal power fluctuates widely with the distance in the near zone [34] while it is relatively stable and thus more predictable in the far zone. After a certain distance that is sufficiently far from A comparison between measured and simulated power decay along the tunnel at four test frequencies (horizontal polarization).…”

Section: Attenuation Constant Measurementmentioning

confidence: 99%

Attenuation Constants of Radio Waves in Lossy-Walled Rectangular Waveguides

Zhou¹,

Waynert²,

Plass³

et al. 2013

PIER

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Abstract-At the ultra-high frequencies (UHF) common to portable radios, the mine tunnel acts as a dielectric waveguide, directing and absorbing energy as a radio signal propagates. Understanding radio propagation behavior in a dielectric waveguide is critical for designing reliable, optimized communication systems in an underground mine. One of the major parameters used to predict the power attenuation in lossy waveguides is the attenuation constant. In this paper, we theoretically and experimentally investigate the attenuation constants for a rectangular waveguide with dielectric walls. We provide a new derivation of the attenuation constant based on the classic Fresnel reflection coefficients. The new derivation takes advantage of ray representation of plane waves and provides more insight into understanding radio attenuation in tunnels. We also investigate the impact of different parameters on the attenuation constant, including the tunnel transverse dimensions, permittivity, conductivity, frequency, and polarization, with an aim to find their theoretical optimal values that result in the minimum power loss. Additionally, measurements of the attenuation constants of the dominant mode at different frequencies (455, 915, 2450, and 5800 MHz) for a straight concrete tunnel are presented and compared to theoretical predictions. It is shown that the analytical results match the measured results very well at all four frequencies.

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Section: Attenuation Constant Measurementmentioning

confidence: 99%

Attenuation Constants of Radio Waves in Lossy-Walled Rectangular Waveguides

Zhou¹,

Waynert²,

Plass³

et al. 2013

PIER

View full text Add to dashboard Cite

show abstract

“…For the measurements, authors of [16]- [19] presented the measurement results of propagation characteristics in circular tunnels at 450 MHz and 900 MHz, arched railway and road tunnels at 400 MHz, arched railway tunnels at 900 MHz, subway tunnels at 2.4 GHz, respectively. For the modeling approaches, many researchers proposed modal analysis based on waveguide theory [20], models based on geometrical optics (GO) approach [21], [22], numerical models based on vector parabolic equation (VPE) techniques [23], and empirical and stochastic models [24] based on measurements (two-slope models [25], [26], three-slope model [27], four-slope model [17], [28], fivezone models [29]- [31], etc.). Both these experimental and theoretical studies systemically form the understanding of wave propagation in tunnels.…”

Section: Introductionmentioning

confidence: 99%

Measurements and Analysis of Large-Scale Fading Characteristics in Curved Subway Tunnels at 920 MHz, 2400 MHz, and 5705 MHz

Guan

Zhang

et al. 2015

IEEE Trans. Intell. Transport. Syst.

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Abstract-Wave propagation characteristics in curved tunnels are of importance for designing reliable communications in subway systems. This paper presents the extensive propagation measurements conducted in two typical types of subway tunnelstraditional arched "Type I" tunnel and modern arched "Type II" tunnel-with 300-and 500-m radii of curvature with different configurations-horizontal and vertical polarizations at 920,2400, and 5705 MHz, respectively. Based on the measurements, statistical metrics of propagation loss and shadow fading (path-loss exponent, shadow fading distribution, autocorrelation, and crosscorrelation) in all the measurement cases are extracted. Then, the large-scale fading characteristics in the curved subway tunnels are compared with the cases of road and railway tunnels, the other main rail traffic scenarios, and some "typical" scenarios to give a comprehensive insight into the propagation in various scenarios where the intelligent transportation systems are deployed. Moreover, for each of the large-scale fading parameters, extensive analysis and discussions are made to reflect the physical laws behind the observations. The quantitative results and findings are useful to realize intelligent transportation systems in the subway system.

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“…-For the tunnel scenario, the authors of [11] and [12] developed a ray optical approach to generate the impulse responses of the transmission channels in high-speed railway tunnels. Furthermore, the propagation situation in the near-region of different types of tunnels was clarified by analytical modeling the division point between different propagation mechanisms [13]- [16]. By using the distributed antenna systems, two sets of measurements were conducted in realistic tunnels at 900 MHz for global systems for mobile communication for railway (GSM-R) [17] and at 2.4 GHz for communications-based train control systems (CBTCs) in [18] and [19], respectively.…”

Section: Introductionmentioning

confidence: 99%

Empirical Models for Extra Propagation Loss of Train Stations on High-Speed Railway

Guan

Zhang

et al. 2014

IEEE Trans. Antennas Propagat.

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Train stations are one of the largest and most unavoidable obstructions for electromagnetic wave propagation on a highspeed railway. They can bring about severe extra propagation loss, and therefore, lead to poor coverage or handover failure. However, their influence has been rarely investigated before. Based on rich experimental results of 930 MHz measurements conducted on train stations of high-speed railway in China, this paper proposes two empirical models for the extra propagation loss owing to train stations for the first time. The extra loss depends on four conditions: the distance between the transmitter (Tx) and the train station, the type of the train station, the track carrying the train, and the propagation mechanism zones. Hence, the models are established for every case of all the combinations of these four conditions. The validation shows that the proposed models accurately predict the extra propagation loss and support an effective way to involve the influence of the train station in the simulation and design of the signaling and train control communications systems.

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Propagation Mechanism Analysis Before the Break Point Inside Tunnels

Cited by 18 publications

References 10 publications

Attenuation Constants of Radio Waves in Lossy-Walled Rectangular Waveguides

Attenuation Constants of Radio Waves in Lossy-Walled Rectangular Waveguides

Measurements and Analysis of Large-Scale Fading Characteristics in Curved Subway Tunnels at 920 MHz, 2400 MHz, and 5705 MHz

Empirical Models for Extra Propagation Loss of Train Stations on High-Speed Railway

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