Electromagnetic field exposure monitoring of commercial 28-GHz band 5G base stations in Tokyo, Japan

Authors: Liu S, Tobita K, Onishi T, Taki M, Watanabe S

Year: 2024 May 22

Category: Exposure Assessment, Bioelectromagnetics

Journal: Bioelectromagnetics

DOI: 10.1002/bem.22505

URL: https://pubmed.ncbi.nlm.nih.gov/38778514/

Abstract

Overview

Fifth generation (5G) wireless communication is being rolled out around the world. This study presents the latest radio frequency electromagnetic field (EMF) exposure measurement results for commercial 28- GHz band 5G base stations (BSs) deployed in the urban area of Tokyo, Japan.

  • Measurements were conducted under realistic traffic conditions using a 5G smartphone with omnidirectional and horn antennas.
  • Electric-field (E-field) intensity was found to be much lower (<-38 dB) than established exposure limits in all cases.

Measurement Details

  • E-field intensities for traffic-off cases showed no significant difference between antennas (max difference 3.6 dB).
  • For traffic-on cases, the omnidirectional antenna could undesirably capture radio waves from the smartphone, resulting in 7–13 dB higher E-field intensity compared to the horn antenna.
  • Comparative results between 4G LTE BSs, sub-6-GHz, and 28-GHz band 5G BSs were discussed along with recommendations for meaningful EMF exposure data acquisition.

Findings

  • All E-field intensity measurements were within the exposure limits established by ICNIRP and IEEE/ICES.
  • The maximal time-averaged E-field intensity (118 dBµV/m) accounted for only 0.016% of the regulatory limit.
  • E-field intensity varied with measurement height (variance of 10–25 dB across spots).
  • For the horn antenna, a 23–27 dB rise in E-field intensity was observed during traffic-on compared to traffic-off, while for the omnidirectional antenna, the increase was 19–37 dB.

Conclusion

  • The study supports standardization of measurement methods for quasi-millimeter/millimeter wave 5G BSs.
  • Despite exposure being well below safety limits, it is crucial to continue monitoring as 5G deployment expands, particularly considering the reflections and scatterings that can increase localized exposure in real-world environments.

Important: Although all exposures were within current guidelines, there remains a connection between EMF exposure from 5G base stations and potential health risks, necessitating continued vigilance, measurement and research as 5G technologies expand geographically and technologically.

5G electromagnetic fields EMF exposure base stations Tokyo radiofrequency measurement methods
← Back to Stats