real world 5G testing
 

hi,
I just realized that the FAA list of 50 airports that have some reduced-power 5G operations ((my wording)) is not complete.
For whatever reasons, airports like Atlanta and Denver aren´t in.
I think the networks will install normal, high-power 5G stations near those places- lots of people, lot´s of purchasing power...
AND: lots of airplanes will fly there. With normal radio-altimeters. Got to remember that they are on, non-switcheable, from the moment
aircraft power-up at the gate to parking and shutdown.
Consequently, high power 5G and altimters will operate close to each other at Atlanta and Denver.

It will be interesting to watch.

K

Airports with 5G Buffers | Federal Aviation Administration (faa.gov)
The 50 Airports with 5G Buffer zones are considered safe, and so any airport not on the list is not considered safe?!? I wonder therefore the NOTAMs restricting operations will be limited to the non-listed airports...

As of Monday 10 Jan (around noon EST)
 

Website of ALPA-International is running an information-intensive page on the 5G deployment situation:

5G C-Band, NOT Cleared for Takeoff - ALPA

Also, from Politico's Transportation newsletter, the following (quoted verbatim) about the posture of the major airports organization w.r.t. the situation:

AIRPORTS AREN’T HAPPY: The Airports Council International – North America on Friday called the FAA's analysis "irrelevant,” arguing that the ripple effects of the deployment will hit the entire national airspace hard, including flight cancellations and delays. Last week’s deal pushed the 5G expansion date to Jan. 19, and AT&T and Verizon agreed to employ additional protections at certain airport zones until July.

“Despite eleventh-hour efforts to resolve obvious concerns that could have been addressed months ago, this attempt at a short-term fix does not address a number of critical uncertainties about the potentially adverse impact of 5G on certain low visibility approaches,” ACI-NA President and CEO Kevin Burke said in a statement.” This so-called fix will create winners and losers within the airport community, and the entire aviation system will suffer under the terms of this deal.”

What kind of crazy excuse for a plan is this? It satisfies no-one.

The cellular side are concerned because they can't use C band at many airfields.
The aviation side are concerned because they don't have protection near many other airfields.

Are the unprotected airfields being used as an unwilling test case, with future regulations depending on whether there are many incidents at them over a period of time?

There are just too many variables of equipment, operation and terrain for such a plan to be adequate. A merely representative test based on a subset of conditions answers nothing. As observed above, aviation has never worked this way.

An issue on this scale, involving potential risks to life as well as billions of dollars, requires a properly organised test regime based on equipment specifications and actual worst-case physical operation.

Hi,
found a bit of a test description from here in Europe. 1 test in Norway and France.
https://cept.org/Documents/ecc-pt1/6...-compatibility
unzipp, look at the larger document.

The tests don´t look like the more comprehensive version Sallyann1234 prefers.....but they are for the lower power, more freq. separation conditions here in Europe. So, maybe they are ok as a first try....
Looking forward to seeing the US version of real-world tests.
K

NOTAMs have been issued, effective on 19 January (when 5G is turned on). Example:

!FDC 2/3714 SFO IAP SAN FRANCISCO INTL, SAN FRANCISCO, CA. ILS RWY 28R (SA CAT I), AMDT 15A ... ILS RWY 28R (CAT II - III), AMDT 15A ... ILS RWY 28L (SA CAT II), AMDT 27B ... PROCEDURE NA EXC FOR ACFT USING APPROVED ALTERNATIVE METHODS OF COMPLIANCE DUE TO 5G C-BAND INTERFERENCE PLUS SEE AIRWORTHINESS DIRECTIVES 2021-23-12, 2021-23-13 2201190500-2401190501EST

Now the fun starts....

Yes.... 1400 Notam....approximately. :confused:

IFALPA 13 Jan 2022
 

"Maintaining Safe Operations with Radar Altimeter Interference from 5G" issued by IFALPA (based on ALPA-International).
Indexed as 22SAB01 superseding and updating prior bulletin on same topic (21SAB16)
Link (from IFALPA website):

22sab01-maintaining-safe-operations-with-radar-altimeter-interference-from-5g.pdf (ifalpa.org)

So now we know how tests are to be done. Every flight is to be a test, and every radar altimeter is to be considered unreliable near airports.
How does the pilot, perhaps under pressure from other adverse factors, decide whether the radalt reading and the systems connected to it are right or wrong?

And all the pax in the back will be unwitting participants in the test...

Only the fixed Antennae?
 

How much of a problem is the signal from a mobile phone (or many mobile phones)? Is this a signal strength issue?

You can control where the fixed antennae are but not where mobiles are used. And they are certainly not angled downward.

Doesn’t a mobile send out a “squitter” from time to time to test network availability? On all possible bands?

And are there other items on these bands - stage wireless or sports equipment?

It's extremely unlikely that handsets could cause a problem. They operate at much lower power than the base stations, and they respond at lower frequencies in the bottom part of the C band. ​​​​​​​
______

​​​​​​​Let's be clear about what is happening here. There is a potential issue of interference to radar altimeters from C band cellular, which calculations suggest might happen. For technical reasons, the risk is likely to be greatest in the USA.

At the moment, both sides are walking around the issue by restricting operations and/or reducing reliance on equipment. For obvious reasons, these have to be temporary measures. ​​​​​​​​​​​​​​​​​​​​​​​​​​​​

​​​​​​​What seems to be missing at the moment is any move to test whether the interference would actually exist under normal operations, and to what extent.​​​​​​​​​​​​​​

There is now reporting that G5 interference is particularly problematic for the B787. Apparently it uses RA data for air ground logic switching and interference may effect spoiler and reverser operation :uhoh:

FAA "Continued Airworthiness Notification"
 

U.S. FAA has issed CAN-2022-01-2, "Continued Airworthiness Notification to the International Community" dated Jan. 14, 2022.
Subject is 5G interference as it affects certain functions or operations of 787 aircraft, worldwide.

(Apologies, not accessing FAA link to post here - but it's quite e-z to locate)

Also, Satcom_guru has technical information in posts on the Tw soc media platform (which is how this SLF/atty learned about the referenced FAA CAN).

Sigh, another own goal for Boeing engineering…..

Progress:

Quote:

---

Collaborative Work Underway to Reduce Delay, Cancellation Risk
Approved radio altimeters will allow commercial aircraft to continue low-visibility landings in the 5G C-Band deployment areas.

---

See updates on https://www.faa.gov/5g

Perhaps a dumb question: The folks that allocate bandwidth for use - would they not have known all the devices likely to operate in a given band? Or, should they have known?

An update on the BBC web-site https://www.bbc.com/news/business-60036831

2 weeks
 

...were enogh to find out some hard info on 5G and radioaltimeter compatibility.
Amazing.
So, how much do we know in 2 months ?
and....what about the year that went by.. ?

Shrug. As bystander, I can only wonder at what happens.

I think that’s a reasonable summary. The other thing to add is that that FAA appear to be in full-defence bureaucrat mode having been caught with their pants down over the 737 Max, and there also seems to be a political infight between them and the FCC; toys are exiting prams all over the place and air transport is collateral right now...
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