September 2023 | NTIA Special Publication SP-23-570

Further 5G In-Air Field-Strength Measurements for Radar Altimeter Research

Frank H. Sanders; Kenneth R. Tilley; Geoffrey A. Sanders


Ongoing NTIA/ITS research shows that it can be possible for 5G base stations to safely co-exist with safety-of-life radar altimeters. This video is a follow up to SP-22-560, “5G In-Air Field-Strength CoLT Measurements for Radar Altimeter Research." It provides more detailed information about the testing introduced in SP-22-560 as well as a description of follow-on testing undertaken after the original video was published. A very brief summary of results reported in NTIA Technical Report TR-22-562, “Measurements of 5G New Radio Spectral and Spatial Power Emissions for Radar Altimeter Interference Analysis” (October 2022) is provided as well as a description of mitigation measures being implemented to protect radio altimeters from interference through improved filtering of signals from outside their allocated bands.

NTIA’s Boulder laboratory, ITS, performed measurements of the unintentional antenna radiation from 5G base stations, to quantify exactly how much power will impinge on aircraft flying near such tower locations. In this video, we briefly describe in lay terms the concern for 5G versus radalts. We go on to show how we set up and performed airborne 5G radiation measurements around such transmitters at the Department of Commerce’s Table Mountain field site north of Boulder. Video sequences show viewers the putative problem, the setup for airborne measurements, and a sampling of some of the measurements themselves. The video sequences, including some data examples, allow viewers to understand qualitatively how ITS captured measurement data. Exactly analyzed data results are provided in "Measurements of 5G New Radio Spectral and Spatial Power Emissions for Radar Altimeter Interference Analysis", NTIA Technical Report TR-22-562, October 2022. This video is an overview of our approach to resolving this spectrum engineering problem.

Related Publications:

NTIA Technical Report:
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For technical information concerning this report, contact:

Frank H. Sanders
Institute for Telecommunication Sciences
(303) 497-7600

To request a reprint of this report, contact:

Lilli Segre, Publications Officer
Institute for Telecommunication Sciences
(303) 497-3572

Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.

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