Effects of Crowd Density on Radio Propagation at 24 GHz in a Pedestrian Tunnel for 5G Communications

Abstract

In this paper, we report the results of radio propagation characterisation in a pedestrian tunnel with different crowd densities at 24 GHz using commercial ray-tracing software called Wireless InSite. The 3D empty tunnel and human body models we created using computer-aided design software and imported into Wireless InSite. The tunnel model is based on a pedestrian tunnel connecting Suria and KLCC, which is located in the heart of Kuala Lumpur. Five three-dimensional (3D) human body models with different levels of detail were developed and tested. The crowd densities investigated were 0, 0.05, 0.1, 0.15 and 0.2 people/m 2 which correspond to 0, 25, 50, 75, and 100 people, respectively, in the study area. The results show that the path loss exponent, log-normal shadowing's standard deviation, and fluctuation in received power increase as the number of people increases. When the crowd density is above 0.1 people/m 2 , the path loss exponent of the large-scale path loss model is higher than that of the empty tunnel. The results of this study are also useful for understanding the effects of human crowds on millimetre wave propagation in indoor tunnel-like environments such as hallways, enclosed corridors, mines, and transportation tunnels. The findings contribute to increasing the effectiveness of network planning and deployment for 5G communication, especially in pedestrian tunnels.INDEX TERMS 5G communications, human crowd shadowing, millimetre wave, pedestrian tunnel radio propagation, ray-tracing A. MILLIMETER-WAVE PROPAGATION IN TUNNEL

Closed-Form Hyper-Rayleigh Mode Analysis of the Fluctuating Double-Rayleigh with Line-of-Sight Fading Channel

“…Full hyper-Rayleigh regime is the most interesting for communication security tasks: There is a heavily obstructed LoS with the intensive fading in the channel. This occurs, for example, in urban areas, inside buildings or at public places, where a lot of people create random, temporary and heavy line-of-sight shadowing [72]. The other two regimes correspond to various scenarios of LoS shadowing, depending on visibility for FSO communication [73], scattering from inhomogenities or turbulence influence in UWOC and when using RF communication systems at relatively large distances, e.g., up to 500 m at 3.5 GHz in urban area [71].…”