28 GHz Indoor and Outdoor Propagation Analysis at a Regional Airport

TL;DR

This study investigates 28 GHz mmWave propagation at a regional airport, revealing indoor environments have lower path loss and richer scattering than outdoor areas, with significant indoor-to-outdoor losses affecting coverage.

Contribution

First comprehensive measurement of 28 GHz propagation characteristics at a regional airport, comparing indoor, outdoor, and indoor-to-outdoor scenarios using a channel sounder.

Findings

Indoor environments exhibit lower free-space path loss.

Indoor scattering is richer, improving coverage.

Indoor-to-outdoor propagation experiences high losses.

Abstract

In the upcoming 5G communication, the millimeter-wave (mmWave) technology will play an important role due to its large bandwidth and high data rate. However, mmWave frequencies have higher free-space path loss (FSPL) in line-of-sight (LOS) propagation compared to the currently used sub-6 GHz frequencies. What is more, in non-line-of-sight (NLOS) propagation, the attenuation of mmWave is larger compared to the lower frequencies, which can seriously degrade the performance. It is therefore necessary to investigate mmWave propagation characteristics for a given deployment scenario to understand coverage and rate performance for that environment. In this paper, we focus on 28 GHz wideband mmWave signal propagation characteristics at Johnston Regional Airport (JNX), a local airport near Raleigh, NC. To collect data, we use an NI PXI based channel sounder at 28 GHz for indoor, outdoor, and indoor-to-outdoor scenarios. Results on LOS propagation, reflection, penetration, signal coverage, and multi-path components (MPCs) show a lower indoor FSPL, a richer scattering, and a better coverage compared to outdoor. We also observe high indoor-to-outdoor propagation losses.