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Re: What do you think about this airline vs 5G brouhaha?


From: Tom Beecher <beecher () beecher cc>
Date: Wed, 19 Jan 2022 11:22:23 -0500

It's also relevant that the spectrum surrounding the 4.2-4.4 range has not
been an empty desert. It has been used for satellite downlink since the 60s
I think?

Yes, there are surely tons of differences in RF characteristics between the
two. But let's be honest. Analysis would have been done decades ago on the
impact of spurious emissions from sat downlinks on RAs, so there should be
at least a baseline to work from.

Either way this should not be a discussion now. This clearly was discussed
early in FCC filings, questions were asked, data was presented, and all
these parties signed off.

On Wed, Jan 19, 2022 at 11:13 AM Tom Beecher <beecher () beecher cc> wrote:

Altimeter Band : 4.2Ghz - 4.4Ghz

VZ and AT&T agreed (long ago) to reduce power and stay inside 3.7Ghz -
3.98Ghz once the full deployment was done, staying 200MHz away from
altimeters.

In Japan, they have been running 5G for over a year now up to 4,1Ghz, and
restarting again at 4.5Ghz. Only 100MHz of guard on either side of the
altimeter band. I think EU is close-ish, but not totally sure.

I can't find a single report or study that has shown radio altimeter
issuers in Japan since 5G was turned on there.

Aside from a single study which a LOT of smart people have called out
flaws in, there isn't much out there that proves there WILL be interference
with altimeters, just a lot of FUD that says it MIGHT. I dunno what the
angle is, but this has turned into a shitshow.


On Tue, Jan 18, 2022 at 3:32 PM Michael Thomas <mike () mtcc com> wrote:


I really don't know anything about it. It seems really late to be having
this fight now, right?

Mike



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