[Sanddancer]

One individual home router operating illegally won't do much to increase the noise floor, but each router operating illegally adds that much more to the background noise and makes it that much more difficult for the weather radar to function properly. So yes, they were doing harm to airport operations. It's just like light pollution -- one light won't block out the stars, but a million will.

[wtallis]

Do you have specific knowledge that diffuse ground-based access points impair the narrow beam TDWRs at issue, or are you just making a broad generalization? It's a decent analogy, but I can think of quite a few differences between a short range weather radar and a radiotelescope.

[Sanddancer]

It was one of the things discussed when making the decision to allow restricted use of the frequencies. Also, keep in mind that more than just airport weather radar use the frequency range in question. That frequency range is also used for satellite uplinks and downlinks. There was a lot of research put into the FCC's decision before it was enacted.

https://www.ntia.doc.gov/files/ntia/publications/ntia_5_ghz_...

https://apps.fcc.gov/edocs_public/attachmatch/FCC-14-30A1.pd...

[wtallis]

Those are informative but rather long documents. Are there any specific portions you'd like to call my attention to? Because I'm seeing statements like "There have not been any cases of TDWR interference identified for other unlicensed device applications" (referring to things other than outdoor point to point links), and the sole satellite communications provider operating in the U-NII-1 band being concerned only with limiting the power radiated upwards from outdoor access points and unconcerned with indoor access points.

For such a well-studied topic and with such strong regulation on the table, there really ought to be something relevant and approaching a smoking gun to point to.

[yuhong]

And how many home users in practice even modify the firmware in the first place.