U.S. airlines warn 5G wireless could wreak havoc with flights

Dhenalau · 16-12-2021 12:20pm #1

https://www.reuters.com/business/aerospace-defense/us-airlines-warn-5g-wireless-could-cause-havoc-with-flights-2021-12-15/

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Major U.S. air carriers warned on Wednesday that plans by wireless carriers to use spectrum for 5G wireless services starting Jan. 5 could disrupt thousands of daily flights and cost air passengers $1.6 billion annually in delays.

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I haven't seen any similar news in Europe?

Do we have a different system?

cml387 · 16-12-2021 12:57pm

The explanation the FAA have made is that it might interfere with the radar altimeter. I guess that would have consequences for autoland and CAT III approaches.

zg3409 · 16-12-2021 1:14pm

I don't think the same frequencies here are used for radar altimeter. If you read the details the altimeters are actually on a different frequency to the 5G. The extra caution is on cheaper/older altimeters that may not filter out nearby frequencies that did not have strong signals in the past. Over a city with lots of 5G, the signal would be crazy strong, and the altimeters in general would be very sensitive expecting to hear a ping reflected back from the ground. It may also not give the pilot an error or error on display of wrong radar altitude. Often these systems are used for automatic landing, but also automatic ground collision avoidance, which may fail silently if the radar altimeter starts to become dodgy over time. In the main I think it's the industry pushing back as they don't want to upgrade existing systems, or even fully test older systems. The reality is the frequencies are already sold to the highest bidder.

HTCOne · 16-12-2021 6:22pm

I don't think the 5G in Europe goes above 3.7 gHz unlike what's about to happen in the US so not an issue here yet.

bk · 16-12-2021 9:05pm

5G is a technology that can operate on many different frequency bands, with radically different characteristics and what frequencies are used differs around the world based on licensing.

In Europe, it is licensed to use, 700MHz, 3.6GHz and 26GHz bands. Currently only the first two are licensed in Ireland.

3.4GHz to 3.8GHz is licensed for use here. This frequency was previously used for MMDS broadcasts for decades in Ireland.

Radio Altimeters appear to use 4.2 to 4.4GHz, so that is a pretty big 400MHz guard band in between.

Given that the 3.6GHz 5G is already in operation here and was used for MMDS for decades, I’d assume we would have already heard if there were any issues with it here by now.

In the US their 5G mid band frequency goes up to 4GHz, so a smaller 220MHz guard. Though that is still quiet a lot.

Interesting article on the subject here:

https://arstechnica.com/tech-policy/2021/11/faa-forced-delay-in-5g-rollout-despite-having-no-proof-of-harm-to-aviation/