IN-SITU 5G NR BASE STATION EXPOSURE OF THE GENERAL PUBLIC: COMPARISON OF ASSESSMENT METHODS

Abstract

New measurement methods and equipment for correct 5G New Radio (NR) electromagnetic field (EMF) in-situ exposure assessment of instantaneous time-averaged exposure (Eavg) and maximum extrapolated field exposure (Emax) are proposed. The different options are investigated with in-situ measurements around 5G NR base stations (FR1) in different countries. The maximum electric field values satisfy the ICNIRP 2020 limit (maximum 7.7%). The difference between Emax and Eavg is <3 dB for the different measurement equipment at multiple sites in case there is only self-generated traffic. However, in a more realistic scenario, Eavg cannot be used to assess the exposure correctly due to influence of other users as the spatial distribution of user equipment (UE) influences Eavg, while Emax is not affected. However, when multiple UEs are collocated, there is no influence of the number of UEs. A broadband measurement can give a first impression of the RF-EMF exposure up to 700 m, but is not enough to assess the 5G-NR exposure.

Comparison of Low-Cost 5G Electromagnetic Field Sensors

“…These will be the baseline for further analysis. Both are commercially available setups and have been used in a multitude of studies [ 9 , 10 , 11 ].…”

“…The Clampco antenna can internally switch the respective axis, which allows for sequential measurement of the components. The settings for the SA setup can be found in [ 11 ].…”

“…For this study, a tri-axial antenna (3502/01) with a frequency range of 420 MHz to 6 GHz was used. However, for in-depth analysis of the 5G NR signal, compared to the FSV-30, the parameters are less adjustable [ 11 ].…”

“…( a ) Horizontal configuration of Figure 3 c,d; ( b ) Vertical configuration of Figure 3 a,b. Red line: FSV (±3 dB is also shown because of uncertainty of SA setup [ 11 ]).…”

RF-EMF Exposure near 5G NR Small Cells

“…In addition, maximum power densities at close distances (down to 1 m) of 5G small cells operating at 28 GHz (with AAS) were simulated in [ 9 ] for several transmission powers and antenna gains. Furthermore, in situ measurement methodologies for 5G new radio (NR) signals have been presented in, e.g., [ 2 , 10 , 11 , 12 , 13 ] for frequencies below 6 GHz (NR Frequency Range (FR) 1) and in, e.g., [ 14 , 15 , 16 ] for frequencies above 24 GHz (NR FR2, also called millimeter waves or mmWaves).…”