Thank you for your comment. I think I see your point of view. There are some points missing I believe. The auctions started if you scroll down the article sinc

Thank you for your comment. I think I see your point of view. There are some points missing I believe. The auctions started if you scroll down the article since 2018 (outside the US) for the neighboorhood in question. https://www.spglobal.com/marketintelligence/en/news-insights/research/us-c-band-auction-becomes-worlds-costliest-mid-band-5g-auction-yet https://www.spglobal.com/marketintelligence/en/news-insights... Nobody raised a flag then. And nobody tried to stop the auctions. FCC has full jurisdiction on this. The C band is the popular one as the article also stresses. Yes FAA complained in 2020 and tried to delay the auction. To even get to the auction the 5G workgroup has been simulating these ranges since 2014 at least (from personal knowledge). There is no chance the engineers working in the neighborhood bands did not know as at least word of mouth was out for anyone doing RF, WiFi, or with interference channels. If you look at the 2016 European 5G annual journal the 3.5Ghz area is mentioned. https://5g-ppp.eu/annual-journal/ https://5g-ppp.eu/annual-journal/ (The bands 42 and 43 which are the ones on question where mentioned that is.) In 2017 FCC did the RFC for the auction. This is the biggest auction ever. Aviation Spectrum Resources (ASRI) was testing and passing altimeters (initial test done and submitted 2019). FAA and various altimeter developers did nothing. (See https://5gamericas.org/wp-content/uploads/2021/07/Mid-Band-Spectrum-and-the-Co-Existence-with-Radio-Altimeters.pdf https://5gamericas.org/wp-content/uploads/2021/07/Mid-Band-S...) If you see the article I shared in prior post, FAA has approved radio altimeter models and has disproved others. In 2011 there was an assessment of the neighborhood bands interference as part of what they called NTIA Fast Track evaluation. And they raised interference issues with current spectrum and practices. FAA and developers did nothing. FAA needs to pay to properly deploy antennas like other countries have for years, in airports and/or have someone buy the spectrum. 40 countries did it right already. Worst case, they had since 2011 to do this. P.S. When you build and antenna/receiver you are the one responsible for staying in spectrum. There is 200 mhz fallow. You can't just go around building devices that will get affected even with a 200 MHz buffer. Nobody is invading their spectrum.