5G Cellular Vs the Airlines. The Good News and Bad

Just some airlines executives that are like a rooster and claiming credit for the sunrise. See https://www.5gandaviation.com/.

5G interference fortunately is a short-range issue, as those frequencies have a limited range. That is why so many transmitters/receivers are required. For those near airports, just hope that the 4G alternative is around for a while longer.

The Y2K issues were real. Most of these problems were averted because of massive proactive actions and huge efforts that were taken to avert disasters and major inconveniences from computer date programming issues. So almost nothing happened, not because it was "fake" but because it was real and attended to.

I'm no expert but there are different bands within 5G. I found this site and it will probably give you more info than you wanted to know about 5G

https://www.gsma.com/spectrum/5g-spectrum-guide/

Here is a perspective from T-Mobile

https://www.t-mobile.com/business/resources/articles/5g-mid-...

Here's an article from CNBC written in 2020.

https://www.cnbc.com/2020/01/09/what-is-5g-heres-what-verizo...

Caused by short sighted programming where all years?were presumed to be > 1899 and < 2000.

Short sighted designs likely because of trying to minimize external storage space.

The standard size for a data record was the 80 byte computer card, every byte you could save counted. Many of us who coded those old Cobol and Fortran and assembly language applications in the late 60's and early 70's never considered that they might still be in use 30 years later or that business would have such a critical dependence on them. But as was said earlier, the crisis was averted by putting a lot of labor in fixing all that code. My company hired additional programmers and we worked hard for several years trying to identify and fix all the problems. 2000 came and went for us without any major issues.

Yes, indeed. The efforts were huge, and the averted problems were real. Not all problems were averted. I, personally, spent nearly all of the first week after doomsday attending to things that had leaked through.

They were not my own bugs, either. So far as I know, I only once ever coded a Y2K bug, and I realized it and fixed it months before doomsday came around. Contrary to the myth, my bug had nothing to do with my trying to save a tiny amount of storage by neglecting to use a full-length year.

There is a case to be made that the effort was inefficient. In my own company (Intel) there was an immensely bureaucratic scheme which required huge efforts most of which were entirely superfluous. But the averted problems were there, were real, and would have caused plenty of trouble left unattended.

The following web page lists the actual frequency for the 5G channels:
https://www.electronics-notes.com/articles/connectivity/5g-m...
It would be interesting to know exactly which frequencies are alleged to cause interference. I live about 1 mile from an airport and we have 5G in the neighborhood. I normally connect with channel n41 which is ~2.5GHz. I haven't heard of any complaints on the news of interference between 5G and airplanes. It would be nice to know what the real story is.
Mark

I didn't mean for this thread to become a discussion on Y2K. I made a poor, misguided reference to it in my original post and I apologize.

Y2K was indeed a potential catastrophe that many (including myself as a Verizon Engineer) worked hard behind the scenes to prevent. Unfortunately, the general public was unaware of this and Y2K became something of a joke.

A 1K memory chip used to be worth $25. Programmers were not short sighted at all. You work with what you got and make the necessary compromises.

Back to 5G:

This gives me agit paiN. Sorry,,, but I couldn't help it.

arst: Boeing, Airbus wade into 5G scuffle, ask Biden admin to delay rollout

https://arstechnica.com/tech-policy/2021/12/boeing-airbus-wa...

There is a LOT going on in the world of commercial aviation in regard to this subject. It will be interesting to see how it works out when you have two government bureaucracies at war with each other.

In theory, the FAA has the bigger club, since they can wave the banner of "safety", but the FCC has big money on its side.

- Tom -

Who will take the fall if, heaven forbid, there is a plane wreck caused by this?

Talking with an engineer working with an aircraft equip manufacturer this morning I learned the primayry issue is in the 3GHz band where 5G resides. Aircraft use the band for radio altimiters that give a precise measurement of the height above ground. Because the sigal from the air is bounced back from the ground the receivers have to have a wide receive bandwidth and if a 5G site is off frequency it can interefere with the altimiter when the plane is trying to land in bad weather.

I really see this differently. (If my tone expresses expertise then I am unintentionally misleading you.)

Apparently the airlines are using radar, specifically for height above ground, whose frequency is proximate to the highest 5G band. (… Both manufacturers and aviation regulators have expressed concerns over C-band 5G signals interfering with radio altimeters on commercial aircraft. The instruments work by beaming radio signals in the 4.2–4.4 GHz band toward the ground and listening for a reply. … from https://arstechnica.com/tech-policy/2021/12/boeing-airbus-wa... ) From my readings I have come to believe that this is exclusively for landing and nothing else. Is this a new radar? I dono. Is this on a different frequency from weather radar and is that more than a “convenience”? I dono.

Can the manufacturers of 5G antennas and cell site installers suppress 5G high band signals from landing paths? My belief (not knowledge since this might be more than a technical issue) is yes. Of course,,, at a cost. Everything is at a cost. Think 737 Max.

So,,, what happens if Airbus and Boeing are 100% correct? 5G carriers will suppress high band 5G signals near landing paths. 5G users along those paths won’t have the highest performing 5G experience, but they will have 5G middle band with better than 4G performance when in that area.

I look forward to any criticism. I am most certainly not fully knowledgeable in this arena.

I just happened apon this:

https://www.ainonline.com/aviation-news/air-transport/2021-1...

AT&T and Verizon announced yesterday that they will roll out their 5G service after a two week, FAA requested, delay.

https://www.nbcnews.com/tech/mobile/5g-rollout-expected-cont...

It appears we will soon see who was right in the airline interference debate.

My guess is a great portion of the issue is due to the design of the radio altimeter's electronics. Doppler shift from the transmitter signal being reflected back allowed for a very wide receiver frequency range. Redesigning the receivers isn't necessarily the problem, it's the cost of replacing all the ones currently in use. Even if the existing receiver can be reworked to tighter specifications, the time needed will still be years.

Our discussion here has only involved the instrumentation in the abstract as though it merely provided a reading. Well,,, it seems that the radio altimeter is sometimes actually integrated into other control operations.

"... The C-Band spectrum, which AT&T and Verizon paid billions of dollars for the rights to use for 5G and plan to switch on Jan. 5, is adjacent to frequencies used by aircraft radar altimeters, which measure the distance to the ground. The devices have a wide range of uses, and in some cases can automatically adjust thrust levels on engines or help pilots land in low visibility. ..." from: https://www.bloomberg.com/news/articles/2021-12-07/aviation-...

A lot of discussion also centers around an exemption zone near runways. Planes in trouble sometimes land on roads. Most carriers provide good service near interstate highways.

This should not have gone this far.

I find it hard to believe that this problem was not foreseen and dealt with long before cellular providers were licensed to use 5G, assuming that they needed an FCC license.

How many EEs do you think write for the popular press? Thus is a complicated topic. I have yet to read anyone question why the receivers in the altimeters don't filter better. I have inferred that US carriers are using more power in C band than carriers in the 40 other countries where 5G is up and running but with smaller exclusion zones than we are talking about here.

"... Why wasn’t this conflict resolved before?

The airline industry and the FAA say that they have tried to raise alarm about potential interference from 5G C-Band but the FCC has ignored them.

The telecoms, the FCC and their supporters argue that the aviation industry has known about C-Band technology for several years but did nothing to prepare – airlines chose not to upgrade altimeters that might be subject to interference, and the FAA failed to begin surveying equipment on planes until the last few weeks. ..." From:
https://www.theguardian.com/business/2022/jan/18/airports-5g...

So,,, why wasn’t this conflict resolved before? Well, there are the big boys: AT&T and Verizon vs. the air carriers. The FAA vs. the FCC in a political environment where the government is told not to interfere in the marketplace. And no one is interested in the altimeter engineering and if it was competently done. (Maybe it was. I don't know.)

If you’re really interested take a look at: https://www.nytimes.com/2022/01/19/business/5g-radio-altimet... . It has lots of interesting references.

I want to pull one sentence, out of context, from a referred article from the Brookings Institution: “… Let’s hope this is more than a gambit to hold 5G hostage to get someone to pay to fix the problem altimeters. …”. This is from : https://www.brookings.edu/blog/techtank/2021/11/22/will-5g-m...

Why not let both sides contribute to upgrading the altimeters, in percentages they work out? Between them, they can afford it.

Watching the Watergate hearings I remember when Sam Ervin asked John Dean (who had been using some of the Republican party’s money) if he believed that the Republican party was an eleemosynary institution. It was a great vocabulary lesson.

So, I ask you if you think that Verizon, AT&T, Boeing, Airbus, Collins Aerospace (I made that one up but wouldn’t be surprised if they made radar altimeters) are eleemosynary institutions? The FAA or the FCC?

As I see it this will be a fight to the death, and I sincerely hope that the death isn’t yours or mine.

Here is another link to the Brookings Institution. It explains that when two federal agencies disagree, the President is supposed to broker a compromise in a timely manner. That wasn't done in 2020. He was preoccupied with other matters.

The FCC first proposed the use of this band in 2018. The head of the National Telecommunications and Information Administration, the President's advisor, had been fired and replaced several times. They were cowed and failed to take any action.

It seems the root cause of today's problem may be political, which may violate this site's Terms of Use.

https://www.brookings.edu/blog/techtank/2022/01/21/did-the-f...

Thanks for the info

Sounds like a Y2K style scare

For anyone still interested...

"FCC considers crackdown on bad wireless receivers after 5G/altimeter debacle"

https://arstechnica.com/tech-policy/2022/03/fcc-considers-cr...

A little to late and a little too lame.

5G is a bad idea. All the towers have to be more dense (more of and closer together) and the towers output more power (up to 15x) than that of 4G.

Remember when they did studies on how people could develop brain tumors from using and or sleeping next to their cellphones when 3G came out.