5G altimeter interference: aviation versus telecoms

The auctioning of the C-band for 5G use has raised concerns in North America that signals could interfere with aircraft altimeter operations. 5GTW asked a filter engineer and a test expert if there’s a problem and how to fix it.

Signals from 5G towers that use the C-band will likely occur at the same time as those transmitted from an aircraft altimeter, though at different frequencies. Image adapted from RTCA report “Assessment of C-Band Mobile Telecommunications Interference Impact on Low Range Radar Altimeter Operations, RTCA Paper No. 274-20/PMC-2073.”

Japan solves 5G airliner conundrum: Keep mobe masts 200m from airport approach paths. That’s it

(And maintain a guard band.) US airliners melt down as rest of world moves on

Really nice, but big challenge is to make sure those aircraft altimeters are actually working within that guard band.


Same in US but is it oob issue due to any leaky RF in any of the side.
Mostly may be in the airplane side.

That’s why old planes were not willing to land in US maybe because of oob altimeters. (AirIndia, etc.)

Has anyone discussed about the 5G vs Altimeter interference issue in US markets for ATT Verizon sub 6 G bands?

I’m going to put a report together, should be published on LinkedIn soon.
US has higher power, that’s the concern.
But FAS cleared 90% of commercial airplanes.
FAA not FAS.

Follows the report:

Verizon is getting its hands on more spectrum sooner than expected: