FAA Says 5G Could Impact Radio Altimeters on Most Boeing 737s (reuters.com) 133
U.S. regulators are warning that 5G wireless operations could affect radio altimeters in most Boeing 737 aircraft and impact crew workload and airplane landings. From a report: The Federal Aviation Administration's directive affects Boeing's 737s, except its 200 and 200-c series, a Federal Register notice posted online on Wednesday said. It added that their "radio altimeters cannot be relied upon to perform their intended function if they experience interference from wireless broadband operations in the 3.7-3.98 GHz frequency band (5G C-Band)." The FAA said in the notice, scheduled to be formally published on Thursday, that regulators had determined that "during approach, landings, and go-arounds, as a result of this interference, certain airplane systems may not properly function". That would result in "increased lightcrew workload while on approach with the flight director, autothrottle, or autopilot engaged, which could result in reduced ability of the flight crew to maintain safe flight and landing of the airplane," it said.
Boeing has deep pockets they can sue att and othe (Score:2)
Boeing has deep pockets they can sue att and others to slow down g5
Re: (Score:2)
Boeing has deep pockets they can sue att and others to slow down g5
This is saying that Boeing built radio-altimeters which can be affected by legitimate use of spectrum that they don't have the right to. If I were Boeing then I'd want to keep very very quiet about this and send out free replacements to all my customers whilst hoping it didn't get widely into the news.
Having said that, since the MD merger, Boeing has likely killed off all the engineering knowledge they have. "If the only tool you have is a hammer, then all problems look like nails". They probably will fi
faa will not like the keep very very quiet part (Score:2)
If I were Boeing then I'd want to keep very very quiet about this and send out free replacements to all my customers whilst hoping it didn't get widely into the news.
Re: (Score:2)
Re: (Score:3)
Re:faa will not like the keep very very quiet part (Score:4, Interesting)
If I were Boeing then I'd want to keep very very quiet about this and send out free replacements to all my customers whilst hoping it didn't get widely into the news.
Can you tell me of the process here? Boeing was already ther and licensed. Next a service moves in beside them, and problems like intermod and harmonic generation cause the new service to splatter out into the Band Boeing is licensed to operate on.
I know it isn't the present day narrative, whch tells us that if Boeing has a problem - it is always Boeing's fault. This is not. This is digital engineers implementing a service that according to the laws of physics, will send RF out into the band that Boeing is licensed to use. I love to bust Boeing's chops, but it is not them who chose to ignore LofP
There is a real problem today, available RF spectrum is simply gone. Here's a chart from the NTIA that is some real eye candy https://www.ntia.doc.gov/files... [doc.gov]
And we keep getting into trouble, because IMO, Digital engineers can't figure out how RF works. Too many believe bandwidth is somehow infinite.
Someone might look at that chart and think that there are places to be had, but propagation and attenuation can wreck a service. It's more than can be gone into on a forum like Slashdot. But we are reaching a point of total saturation.
And this is why we need to look at getting as much digital traffic back into wire and fiber. Because we'll be having to cap things otherwise.
Re: (Score:2)
Can you tell me of the process here? Boeing was already ther and licensed. Next a service moves in beside them, and problems like intermod and harmonic generation cause the new service to splatter out into the Band Boeing is licensed to operate on.
More or less, radio frequency is allocated by the ITU-R which puts some of it down to national use. The national bodies then allocate the use of specific areas of spectrum. When they do that they allocate a specific band and normally put a small gap around that. A certain level of harmonics are allowed but the power in the harmonics has to be much less than in the main band. The power levels allocated in each band in use take into account the expected allowed interference.
Other users of spectrum are expec
Re: (Score:3)
Boeing's allocation only had a limited guard frequency around it. There was no guarantee that adjacent frequencies would not be allocated so they should be ready for that to happen. At the extreme end of interference handling, military radios use both slow and fast frequency hopping and various spread spectrum techniques. Even cell phones have a bunch of techniques in use, including CDMA. Boing could easily have used some of those techniques to handle interference resistance. They chose not to.
As designed, you've got a critical safety mechanism that any random radio ham could interfere with if they chose to. This seems to me to be a lucky discovery for Boeing before some terrorist started taking advantage of their bad design.
Boeing and everyone else using that allocation could possibly start a bit of an Arms Race by ramping up the power of it's radar altimeters. I'm not certain what theirs are right now, but a short pulse train of 100 KW might increase their return signal to the point of overpowering the interference from 5G.
Then again, in crowded areas near airports, it might interfere with the 5G.
In reality, those 2 things should never have been so near each other. But bandwidth is scarce, and the phone companies have th
Re: (Score:2)
Boeing and everyone else using that allocation could possibly start a bit of an Arms Race by ramping up the power of it's radar altimeters. I'm not certain what theirs are right now, but a short pulse train of 100 KW might increase their return signal to the point of overpowering the interference from 5G.
Then again, in crowded areas near airports, it might interfere with the 5G.
Is it within their permitted transmission strength and profile? Yes? Then they should do that. No? Then they should find an alternative like CDMA encoding.
And guess what. 5G is designed to deal with interference. It will cope.
Re: (Score:2)
Boeing and everyone else using that allocation could possibly start a bit of an Arms Race by ramping up the power of it's radar altimeters. I'm not certain what theirs are right now, but a short pulse train of 100 KW might increase their return signal to the point of overpowering the interference from 5G.
Then again, in crowded areas near airports, it might interfere with the 5G.
Is it within their permitted transmission strength and profile? Yes? Then they should do that. No? Then they should find an alternative like CDMA encoding.
And guess what. 5G is designed to deal with interference. It will cope.
This is pretty exciting. I've been in this industry for 30 some years I had no idea that there is a system that is totally interference free! And if you know this - can you give me the citations it is interference free? As well, If you know it, and can't - are you willing to give me some inf that I can get in touch with you? I might be able to offer you a very lucrative position, or point you to people who can
I'm excited for the possibility of learning and maybe even working with you. Up for it? \
Re: (Score:2)
This is pretty exciting. I've been in this industry for 30 some years I had no idea that there is a system that is totally interference free! And if you know this - can you give me the citations it is interference free? As well, If you know it, and can't - are you willing to give me some inf that I can get in touch with you? I might be able to offer you a very lucrative position, or point you to people who can
I'm excited for the possibility of learning and maybe even working with you. Up for it?
No, because either you are being a bit of a troll or apparently in all that time of "working in the industry" you haven't bothered to learn the difference between "interference free" and "cope with interference". In the latter case, you have things like resending the same message; you have things like matching pulse trains or even digital checksums (cryptographic or otherwise) which validate message integrity. You have things like frequency hopping which and frequency reallocation which allow systems which
Re: (Score:3)
Boeing was already ther and licensed. Next a service moves in beside them, and problems like intermod and harmonic generation cause the new service to splatter out into the Band Boeing is licensed to operate on.
That isn't whats happening tho.
There is a guard band between the upper 5G band and the radio altimeter band.
5G isn't spilling past this band, they aren't even spilling significantly past their own band.
What is happening is that older radio altimeters are listening to a far wider band than they are licensed to listen to - they might be transmitting within their own band, but they are listening well down into the new 5G band because of poor receiving filters on most radio altimeters. With weak signals in the
Citation? Or random guess? (Score:2)
A central question here is which is it -
Is the radar too sensitive to frequencies outside the band, or is 5G spilling outside their band?
Or maybe a little bit of both - the radar is sensitive to truly tiny amounts of interference in their own band.
You've said that it's option A, that the radar is sensitive to frequencies outside their assigned band. Do you have a citation for that? Or is that a guess you've phrased as fact?
Re: (Score:2)
As one of my favorite YouTuber's (CuriousMarc) is fond of saying...
Microwave electronics is the blackest of black arts in analog electronics.
Definitely not for everyone! I've recommended analog RF - or at least being deeply immersed in both it and digital - to young people. Problem is, I've worked with so many who believe that analog is dead.
Not so! At this time, you can come close to writing your own ticket if you understand The bizzare world of radio. It's physics, and everything follows the rules. But it is non-intuitive.
They've been trying to figure out how to get me some help, a sort of a paid internship for an up and coming RF person.
Re: Boeing has deep pockets they can sue att and o (Score:5, Insightful)
The fundamental problem is not Boeing. I'm sure they'd be happy to send out a new radio-altimeter transceiver to all equipped jets right away; it's not like refitting the altimeters with better band-pass filters is terribly difficult.
The fundamental problem is the FAA and the way they handle the certification of equipment on any aircraft certified in the United States. In short: something as incredibly simple as "replacing the radio" is not like replacing the radio in your car, where you get something that fits the hole, plug it in, and off you go to the races.
No; the FAA has to wrap all this up in a certification process that is incredibly byzantine and expensive.
So sure, it may take an engineer perhaps a day to redesign the filter for their radio altimeters, and take a QA pass perhaps a week to test the equipment, and a few more weeks to fly the equipment in actual jets to see that it works.
But in order to get a type certification change [faa.gov] from the FAA, you wind up going through a QA process with the FAA that can literally take years. It's an exhaustive process, which is why, for example, a new airplane design for something as seemingly straight forward as a new two-seater single-prop airplane can take at least a decade. And why you can't put off-the-shelf equipment into an airplane, like, for example, putting a Porsche Boxster engine into a single-prop airplane (whose airframe was redesigned to accept it), without going through more rigamarole than a single human being can survive.
It's useful to blame Boeing, because they made the equipment. But there is literally nothing in the world more caught up in red tape than type certification through the FAA--a process that doesn't actually seem to make things safer in commercial aviation. *cough* 737 Max 8 *cough*
And it's why airplanes are hellishly expensive, and why most private pilots wind up flying fleets older than the pilots who fly them.
(Source: used to fly private airplanes before I gave up the hobby after I crashed a few years ago.)
Re: (Score:3)
Actually replacing a radio is as easy as replacing the hardware and signing a couple of papers. I did it for my aircraft because I had to replace the radio due to the change from 25 kHz to 8.33 kHz spacing.
The new component has to be certified on the type and that is hard but it has to be done only once per type but and it's a certification of just the equipment, not the whole aircraft.
Re: (Score:3)
And thus the problem. We're talking about a brand new, newly designed radio altimeter here, not just "plug in a replacement." (That's what updating the band-pass filter means: a whole new model of radio altimeter, even if most of the guts are similar.)
Re: (Score:3)
Yes, that only needs to be done once. And they had years to do it but chose not to.
Re: (Score:2)
Re: (Score:2)
I don't think the process is inherently flawed but corruption and backscratching tend to derail such things, especially since a lot of the certification-process was actually done by Boing in this case to speed things up.
Either way, people died because neither FAA or Boing actually did what they where supposed to do, making sure the aircraft was safe.
Re: Boeing has deep pockets they can sue att and o (Score:5, Insightful)
But there is literally nothing in the world more caught up in red tape than type certification through the FAA--a process that doesn't actually seem to make things safer in commercial aviation. *cough* 737 Max 8 *cough*
On the other hand [wikipedia.org], if you look at actual long-term statistics -- especially excluding general aviation (privately used planes) and only look at commercial flights -- flying is vastly safer now than it was decades ago. Since 2010 there have been 29 deaths on commercial passenger flights. In the 1980s and early 90s, most years had more deaths than the last decade(-plus). In the 1960s, there were 100+ deaths every year, with fewer flights and smaller planes.
Yes, the FAA makes it very expensive to get or change a type certification, and sometimes that process fails. But on the whole, it does make things vastly safer.
Re: Boeing has deep pockets they can sue att and o (Score:5, Insightful)
I would argue the culture of safety that the FAA promulgates, such as cockpit management techniques, and looking at human factors failures as systemic failures rather than personal failures, has done far more to make flying safe.
Re: Boeing has deep pockets they can sue att and o (Score:5, Interesting)
You're cherry picking data here by focusing on accidents that happen in the US, which neatly sidesteps the comment you're responding to which specifically related to safety aboard Boeing metal, specifically the 737 Max 8. Almost 800 people have died worldwide in accidents aboard 737 of various models in the last five years. I will grant that ~150 of those who died were killed by a surface to air missile, but that still leaves >600 dead, a far cry from "29 deaths on commercial passenger flights since 2010."
Re: (Score:3)
I would argue that by including planes that are flown by pilots the FAA doesn't license and maintained by people the FAA doesn't regulate, you are comparing apples and oranges. The FAA doesn't approve an aircraft design and stop there.
Re: (Score:2)
I would argue that by including planes that are flown by pilots the FAA doesn't license and maintained by people the FAA doesn't regulate, you are comparing apples and oranges. The FAA doesn't approve an aircraft design and stop there.
Well, that could be true, except he mentioned the 737 Max, where the faults included problems in the FAA certified planes and not the brave pilots who identified the problems and were able to physically disable parts of the 737 systems but not to overcome the aerodynamic forces to take control of the aircraft after ACARS messed things up.
Without those non FAA pilots and the work they did in their last moments of life, likely we wouldn't have yet identified the problems with the FAAs certification process.
Re: Boeing has deep pockets they can sue att and (Score:2)
I believe you mean MCAS. That was the system that Boeing put into place in an attempt to make the Max8 handle like the previous generation (and this avoid requiring airlines to get their pilots a new type certification). The aircraft itself wasnâ(TM)t inherently bad, just different from previous generations. If pilots treated it like previous generations, bad stuff happened. Which we saw.
Conversely, the Navy Pilots flying the P8 poseidon face similar issues, but because theyâ(TM)re trained for it,
Re: (Score:3)
. If pilots treated it like previous generations, bad stuff happened. Which we saw.
Which is fine except Boeing's biggest marketing point was that you could treat it like the previous generation.
Re: (Score:3)
The fundamental problem is not Boeing. I'm sure they'd be happy to send out a new radio-altimeter transceiver to all equipped jets right away; it's not like refitting the altimeters with better band-pass filters is terribly difficult.
Band pass filters won't do much good for intermod and other interference on the same frequencies. This is the problem, not just the need to sharpen filters.
Re: (Score:2)
Re: (Score:3)
Unless something changed recently, I believe you can only slap whatever you want into your airplane if it's an experimental aircraft. [faa.gov] Otherwise, aircraft airworthiness requirements [faa.gov] apply--and you (more or less) can't turn a screw without a chain of documentation and type certification of the equipment.
Re: Boeing has deep pockets they can sue att and o (Score:5, Interesting)
Boeing has deep pockets they can sue att and others to slow down g5
This is saying that Boeing built radio-altimeters which can be affected by legitimate use of spectrum that they don't have the right to.
That is not how RF works. Intermodulation is a real thing. Many digital engineers don't seem to understand it, but it is real, and it is a law of physics. Digital engineers have given us failures like the Broadband over Powerline, the utter mess of the attempt to to use bandwidth right next door to GPS, and now the 5G allocation.
There are a couple forms of Intermodulation. First is when there is a non-linear interaction, which can happen if there are loose or corroded connections. That's not the big problem here.
The second is when you have multiple frequencies in use that cause new frequencies to be generated as the original frequencies beat against each other. That is what is usually the case in these sort of problems. And beat frequencies to not respect frequency allocation. They don't mention intermod in this article, but if the signals are not dirty - it's the big culprit. https://crsreports.congress.go... [congress.gov] Probably because it seems like black magick. If you just have two signals - it's not to difficult to predict intermod. But if you have many - it isn't human capable unless you want to spend years on the calculations, as each new signal beats against another. Digital signals do add another layer of complexity because their components tend to look like square waves, which are a harmonic producing wonderland.
And at present - my income is from mitigating/eliminating intermod and the out of band problems that occur from transmitters on adjacent bands. Pays well, because few understand the issues, but many understand the results of those issues.
Re: Boeing has deep pockets they can sue att and (Score:2)
The fact that itâ(TM)s literally only one type of aircraft (presumably exactly one radio altimeter design) thatâ(TM)s failing here tells us a lot though. This isnâ(TM)t some complex word interaction of radio frequencies. That would affect far more than one aircraft. This is simply one badly designed radio altimeter. It just happens that itâ(TM)s the radio altimeter used in the single most commonly flown commercial jet airliner.
Re: (Score:3)
The fact that itâ(TM)s literally only one type of aircraft (presumably exactly one radio altimeter design) thatâ(TM)s failing here tells us a lot though. This isnâ(TM)t some complex word interaction of radio frequencies. That would affect far more than one aircraft. This is simply one badly designed radio altimeter. It just happens that itâ(TM)s the radio altimeter used in the single most commonly flown commercial jet airliner.
Not necessarily. What it means is that some of the 737's might be more susceptible. It is in interesting outlook that many here have that if you have an operating and fully functional system, and someone sets up beside you, and splatters rf noise on your section of spectrum - it's your fault. You are in the wrong - not the person who is ending up transmitting junk on your part of the spectrum.
Quick question - this is similar to the time that the phone companies were trying to install a system that ended u
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
they can sue att and others to slow down g5
Sue for what? For their failure to properly design their own equipment to ignore signals out of the frequency range they were designed for?
The airline equipment makers are at fault. Not the companies deploying 5G.
Re: Boeing has deep pockets they can sue att and o (Score:5, Insightful)
they can sue att and others to slow down g5
Sue for what? For their failure to properly design their own equipment to ignore signals out of the frequency range they were designed for?
The airline equipment makers are at fault. Not the companies deploying 5G.
You really don't understand that this is not the fault of the people designing ans using the radar altimiters. The problem is that the interference is from the 5G signals, ending up in a band they are not allocated for. We had a similar problem when another attempt to pretend that a cell phone allocation somehow wasn't going to interfere with GPS signals. People such as myself said it won't work, the digital only engineers said "You're full of shit - these aren't even the same frequency.
So they went into the testing all cockawhoop sure they wouldn't interfere - after all those RF people were negative Nancys.
Fire it up, and the intermod and SQ harmonics wiped out the GPS signals. Just like all of us who knew how RF works said would happen. Another time when the digital guys wanted to deploy Broadband over power net, they couldn't grok that on occasion, people communicate around the world on a few milliwatts at the frequencies they wanted - which would knock ot the frequencies that planes use on circumpolar flights. Ye canna violate the laws of physics!
Re: (Score:2)
Although interference is a big problem, designing a system for radio altimeters that are less susceptible to interference is entirely possible.
For example, you could have at least 3 altimeters of the same design but operating on different bands to make sure you at least have one or two accurate readings.
The real problem here is that none of the parties involved actually communicated with each other in any meaningful way to avoid these type of problems when frequency bands are adjacent or overlap.
Re: Boeing has deep pockets they can sue att and o (Score:5, Informative)
Although interference is a big problem, designing a system for radio altimeters that are less susceptible to interference is entirely possible.
For example, you could have at least 3 altimeters of the same design but operating on different bands to make sure you at least have one or two accurate readings.
The real problem here is that none of the parties involved actually communicated with each other in any meaningful way to avoid these type of problems when frequency bands are adjacent or overlap.
I think that design can be really easy. In fact - If the airlines just cranked up the power they transmit at they could overwhelm 5G. They could even shut it down in the more populated areas.
But the problem is, we have limited RF spectrum. And the services in each allocation are not supposed to interfere with each other. So altimiters probably are operating at maximum allowed power already.
So what we have with that idea of triple redundancy, is exactly where those 3 frequency allocations are going to be? I think most everyone in here believes that this is 100 percent the Airlines fault, that they need to move because 5G has some sort of absolute right to not only it's allocations, but must be allowed to interfere with the services nearby.
So let's say that radar altimiters must not operate on 4200 to 4400 MHz - they lose that allocation brecause 5G is more important, and must be allowed to do as they will. A good chance that that cut of spectrum will not be no man's land.
Next is what I do when people come in looking for spectrum. I have a wall mounted RF spectrum from the NTIA. I direct them to it, and tell them to pick out what they want. Here it is: https://www.ntia.doc.gov/files... [doc.gov]
Because the problem is just that huge. We've pretty much run out of space. UHF frequencies are about as low as the services we're talking about can operate. Below that, then antennas are getting big, and the frequencies are getting propagation effects, and the signals have this annoying tendency to travel around the world, and travel lengths are different depending on what time of day it is.
Then the higher you go, you have to get more transmitters to cover the same distance due to path loss. That's why the highest frequencies 5G uses have a lot more transmitter sites. New York is placing them on streetlight poles. Then we sometimes have to worry about precipitation loss, which can really shut down a system. It's possible to increase power sometimes, but after a while the power needed becomes infinite.
That chart pretty much illustrates the problem. At this point - to provide redundancy, someone would have to lose allocations.
In the end radar altimiters and 5G will have to figure out a way to get along, or else we have a huge problem.
We might be able to have some really sharp cavity filters placed on the 5G transmitters. to keep as much as possible out of the radarspace. We might be able to crank up the power on the altimeter radars to provide a stronger return ping. But dayum, no phone company is going to want that expense. 5G requires so many more stations.
I've seen this problem several times before, when Broadband over Power line (BPL) people tried to home in on the circumpolar airline communications (another weird part of radio that HF works best for them) As well, the BPL folks made an effort to switch part 15 on it's head, by changing it to mandate that licensed operations would have to accept interference from unlicensed systems. They tried installing filters to "notch out" the ham bands" but intermod and the harmonic effects of digital signals made that pointless. The final nail in the coffin was when it was found that a kist with a walkie-talkie could knock out the digital signals over a large radius that would take several minutes to recover. Now imagine all the other low power licensed
Re: Boeing has deep pockets they can sue att and o (Score:5, Informative)
The airline equipment makers are at fault. Not the companies deploying 5G.
The FCC is at fault. They sold something that they had no right to sell. The guard bands that they had a duty to protect surrounding the bands that they had already allocated for radio altimeters.
If someone stole your car and turned around and sold it to some unsuspecting buyer, wouldn't you expect that it would be returned to you? The FCC needs to return the property to it's original owner. And if they can refund AT&T and Verizon for the sale, fine. But I suspect, as with many car thieves, the proceeds have already been spent on crack.
Re: (Score:3)
ATT has almost 3 times the revenue of Boeing. Then add the other cell providers - VZW has twice the revenue of Boeing, and twice as many C-band licenses as ATT. T-Mo has more revenue than Boeing. US Cellular, and Canopy Spectrum are also licensees.
Re: (Score:3)
It seems more likely they'd sue the FAA, if in fact their equipment meets the required specification.
Re: (Score:2)
If their equipment met the required specification, this entire hullabaloo would never have been anything. The radar altimeters are licensed for 4.2GHz and above, and have no business listening below that... definitely not in the 3.98GHz and below band where 5G lives. This whole affair is entirely the fault of crooked airline (or Boeing/Airbus) execs padding their quarterly bonuses by buying substandard equipment and hoping no one would notice.
Re: (Score:2)
If their equipment met the required specification, this entire hullabaloo would never have been anything.
lol you haven't been following this issue. At all.
Kinda late in the 5G game for this concern. (Score:2)
You'd thought someone with authority enough to actually address this long before now, would have.
Ah, I get it... this is a live reenactment of the movie idiocracy
And it seems to be happening in other areas too.
Re: (Score:2)
"may not" and "could" really should have been tested out before releasing this statement. Preferably on a clear day with no passengers... instead we get "something bad might happen".
Bleh.
Re: (Score:3)
"may not" and "could" really should have been tested out before releasing this statement. Preferably on a clear day with no passengers... instead we get "something bad might happen".
Bleh.
Actually, the interference can be seen and measured, as well as simply calculated: https://www.twu557.org/index.p... [twu557.org]
Problem is that the political hacks that make these decisions believe the money the phone companies pay them trump the laws of physics. And I hate to be accused of arguing from authority, but this RF stuff is how I make my money these days. And the new signals are giong to mess with the radar altimiters of any plan who uses their allocated frequencies.
Re: (Score:2)
You'd thought someone with authority enough to actually address this long before now, would have.
Ah, I get it... this is a live reenactment of the movie idiocracy
And it seems to be happening in other areas too.
After the FCC became a stomping ground for political hacks with no technical experience, it seemed like a no brainer to give the Cellphone companies adjacent frequencies. But anyone with technical competence just knew this would happen.
And - it did. The digital signals are intermodding and harmonicing their way right onto the altimeter radar frequencies.
Re: (Score:2)
You'd thought someone with authority enough to actually address this long before now, would have.
Conflicts over RF spectrum have been happening for over 100 years now. The earliest battles involved ending the use of spark-gap systems that effectively used the entire RF spectrum. And yes, the spark-gap incumbents had legitimate safety prerogatives then as well; see RMS Titanic.
This new squabble is entirely normal in the sense that new RF operators have revealed that incumbent RF operators are not really prepared to accommodate the changes that regulators have promulgated, even if theoretically they
Easy fix, no 5G C-Band by Airports (Score:2)
Re: (Score:3)
Re: (Score:3)
Note the approach into LAX passes over most of the basin. [faa.gov] Which means no 5G for anyone living in Los Angeles.
Re: (Score:2)
Which means no 5G for anyone living in Los Angeles
5G can use different frequencies. A loss of one frequency band does not make 5G irrelevant. I say disable the effected frequency band then retrofit the aircraft with shielded altimeters (or whatever fix is required) during regular maintenance. After a couple of years they should be able to enable the disabled frequency band. Now everything works at a minimum cost and with minimum inconvenience.
Re: (Score:2)
Note the approach into LAX passes over most of the basin. [faa.gov] Which means no 5G for anyone living in Los Angeles.
There might be a technical fix. Problem is, it's really difficult to fix signals that are actually right in the band you are allocated for.
The real solution should have been to choose an allocation that wouldn't send intermodulation and harmonics onto the allocation of a life critical service like radar altimetry. But the Political hacks at the FCC years ago thought that the money given to them would overpower the laws of physics.
When anyone knowing a bit about this stuff would have successfully predi
Re: (Score:2)
How is this not an issue for the rest of the planet?
Re: (Score:2)
They don't use those frequencies
Re: (Score:3)
How is this not an issue for the rest of the planet?
Apparently, only Korea and the USA allocated this specific band (3.7-3.98 GHz), The rest of the world does not.
Re: (Score:2)
As others have pointed out, different frequencies.
There's a CNN article here: https://www.cnn.com/2022/01/19... [cnn.com] on that very topic. The Europeans used a lower (and I guess slightly slower) band for 5G, thereby creating a bigger buffer. In addition, there were restrictions on 5G antennas near airports, requirements that they be tilted so as not to send as much of a signal into the airplanes' path, and lower power requirements.
The Europeans knew what they were doing; the FCC, being (as another post mentione
Re: (Score:3)
No. Fuck that. 5G has a right to operate in those areas and their customers will want to use cell phones while at the airport. Obviously. The Aircraft are the ones in violation of the allocation of spectrum, not the operators. The aircraft should be forced to disable those altimeters until non-interfering ones can be retrofitted.
So can you tell me that the 5G service is pemitted to transmit outside of it's band? Can you show me the statutes that allow Cell phones to do that? And it isn't part 15. Radar altimeters are in their band allocation, and the 5G signals are (accidentally) sending interference into the allocated frequencies that they are not allocated for.
Although I suppose when the users of the cell phones jam the altimeter radar because their signals are operating in the altimeter band - the soon to be dead people can
They have had over a decade to fix the issue (Score:2)
Re: (Score:2)
Have they done anything except complain and threaten to sue?
The problem is the people who gave the phone companies the frequencies for a tidy sum, don't understand Electromagnetics. They think that the only time there can be interference is when two signals are on the exact same frequency. So you think they will believe some egghead RF engineer that says it won't work? I submit that they will not.
Re: (Score:2)
This country is run by lawyers and bureaucrats. Lawsuits and paper studies are all they know.
Meanwhile, in other parts of the world, they actually know how to cut metal and pour concrete. And unsurprisingly they have fewer problems of this type than we do.
True, dat.
Politicians and bureaucrats have been taught to not believe anything people with a science background say.
So fix your damned aircraft! (Score:2)
Simple solution... take out the crappy old radio-altimeters and fit some that are a little more modern with adequate levels of "out of band" rejection. It's not rocket surgery -- this early stuff was very poorly designed and should never have been certified in the first place.
Are you sure it is the early ones? (Score:2)
I wouldn't be surprised at all if the older altimeters are more in compliance than the newer ones.
I mean, consider this line: "Boeing's 737s, except its 200 and 200-c series,"
If you hit wikipedia up, you'll find that 737-200s are considered "First generation" 737s. They're unaffected.
It's the later models that are affected.
Re: (Score:2)
Perhaps they're unaffected because they pre-date radio altimeters or have only recently been retrofitted with them.
Re: (Score:3)
Simple solution... take out the crappy old radio-altimeters and fit some that are a little more modern with adequate levels of "out of band" rejection. It's not rocket surgery -- this early stuff was very poorly designed and should never have been certified in the first place.
The problem isn't out of band rejection. The problem is the 5G signals having spurious radiation in the altimeter band.
Now maybe, the radar altimeters can have a massive increase in power - maybe 50 KW or so. Think that in crowded areas that you'd accept the interference to your 5G signal?
Really, the problem is that some of the 5G signals were placed in a part of the spectrum that they shouldn't have been. And politicians don't believe in the laws of physics, so what could go wrong?
Re: (Score:2)
I'm sure they could increase the transmit power on the radio altimeters. That would improve the signal to noise ratio in the receiver stage. Just don't be holding a 5G phone when an airplane flies over. They will get pretty warm.
Could? (Score:2)
They're only saying "Could"? Is it really that hard to set up some experiments and actually figure it out one way or the other?
Radio engineering is often more voodoo (Score:2)
Sadly, this sounds like it actually is the result of experiments. The problem with doing experiments for this sort of stuff is that you want to test every single possibility, and that gets expensive and complicated quickly.
Because radio engineering is still often more voodoo than science, so you could have something like where it interferes only if it hits on the right side, 24 degrees off center, and only for 3 degrees off perpendicular, when it is within 4 km of the transmitter. Which, for some unknown
Ground them bamboo-bombers (Score:2)
They had ample time.
Re: (Score:2)
IIUC, the FAA was complaining about this for ample time, since December 2020, but the NTIA failed to forward the FAA's letter to the FCC because they claimed the FAA was wrong--or maybe because there was a lot of $ to be made in auctioning off the frequency band in question. Indeed, Boeing filed a letter with the FCC in 2018 saying there could be interference, and there were lots of other filings between then and Jan 2022 saying that there could be dangerous interference. But the FCC ignored them all, bec
Shouldn't this be the FCC's fault? (Score:5, Insightful)
Re: (Score:2)
This has actually been going on for years--long before the 5G band was auctioned off. Basically the problematic bandwidth was first proposed under the Trump Administration back in 2017, [cnet.com] and the FAA and the FCC have more or less been going at it since then, with the FCC essentially ignoring the concerns of the FAA until the Biden Administration, after Verizon and AT&T had already spent billions.
Re: (Score:2)
I mean if they allowed the spectrum to be used that was already needed by airplanes, or at least someone didn't do their due diligence before this all started rolling out.
Yes, and no. If the spectrum was needed by airplanes, then it should have been allocated to the airplanes... BUT the airplanes were built to rely on spectrum beyond what was assigned to them. So they exceeded their license when they built them -and got lucky that no one else was using the spectrum at the time.
Re: (Score:2)
My understanding:
From the FCC's perspective, the aircraft are defective and shouldn't be affected by 5G spectrum use. Airline operators must pay to correct the problem.
From the FAA's perspective, a novel use of radio spectrum is interfering with existing life-critical airline equipment. Radio operators must ensure that their use of spectrum doesn't cause a safety risk to the uninvolved public. This means reduced 5G coverage near airports.
They're both right; hence the problems.
Re: (Score:2)
I feel that adults could have reached a viable solution to this problem. But.... I wonder if Ajit Pai figures prominently in this somehow.
Re: (Score:2)
He does, see my posts somewhere above. I suspect Trump figures into it, too.
Re: (Score:2)
Re: (Score:3)
I mean if they allowed the spectrum to be used that was already needed by airplanes, or at least someone didn't do their due diligence before this all started rolling out.
The FCC and DoT are in different branches of government. They have been arguing about this for quite some time. There is one individual who's duty it is to mediate between the two. Unfortunately, it's an elected position [wikipedia.org] that tends to be held by bafoons.
Re: (Score:3)
They did do due diligence. The 5G frequency is different than those used by radio altimeters. It is just close, and older altimeters don't have good enough line filters to limit the radio waves received to the frequency they are supposed to be using.
No they didn't. The ITU published a specific recommendation about the size of the guard band and nature of adjacent bands for radio altimeters and it was ignored because MONEY! You use the term filter as if you don't realise that wide band altimeters are more accurate and the more you filter the less useful your RA becomes.
Ummm... (Score:2)
What is a 'lightcrew'?
Re: (Score:2)
a flightcrew that is "good enough for government work."
Re: (Score:2)
What is a 'lightcrew'?
a flight crew that does not give a F...
To be fair given the quality we've seen of late (Score:2)
This is what happens when you let regulatory capture go too far. Everyone's known about 5G for years now. It goes back to 2008 with serious work dating back to 2012. By why cut into profits when political contributions are cheaper?
Re: (Score:2)
I'm pretty sure you don't know what you're talking about.
And for all you or I know, the political contributions are exactly what caused this fiasco.
GPS gives elevation data (Score:2)
AND position.
This is a bullshit, made up problem.
Re: (Score:3)
GPS gives your elevation, above (nominal) sea level. It doesn't give the elevation of the ground, at least not without a lot of extra data, including accurate charts of the area several miles around every airport you might use, and then has do do a lot of calculating.
Meanwhile a radar altimeter simply pings the ground and tells you how far away it is - no data required, and minimal computation so an instant real-time figure.
Re: (Score:2)
I wanted to respond to this, but I realize that I don't know enough about how radio altimeters work. Do they send a directional pulse downwards at some fixed angle from a point on the bottom of the plane, or do they send out an omnidirectional pulse? It seems like there might be a problem figuring out what "down" is if it's a directional pulse because the roll and pitch of the plane can vary. I remember my daughter's first plane flight where I made a crude pendulum to show her that, when the plane was banki
Re: (Score:2)
Priorities in an era of idiots (Score:4, Insightful)
In normal times, the idea that society would endanger the lives of thousands of people every day just so that some stupid fools can watch cat videos, or porn, or short little selfie videos on their cell phones would be totally absurd. Remember: cell phones have provided plenty of functionality for many years without 5G; we're debating minor extra cell phone features vs airliner safety (plus the safety of people on the ground under the flight paths, of course) and there are blithering idiots actually picking 5G!
Twas not long ago that nobody even had cell phones, let alone smart phones with apps and video playing capabilities, and yet civilization went along just fine. Cell phones, no matter what some stupid screen addict might think, are not necessary; they're a nice-to-have, a convenience.
Radar altimeters on airliners, on the other hand, are rather important, particularly in the approach and landing phase of flight, which often happens over crowded areas of major cities. Sure, we can argue that airlines could replace the radar altimeters, but nothing in aviation is quite that simple; it takes a long time to design new avionics, get them certified, then get them approved for use in particular airframes, etc - YEARS, which translates to huge piles of money as well, in an industry that's always having financial problems. On the other side, we have huge. very wealthy, cell phone companies (both the makers, and the service providers) who simply want to churn even more money by selling the next model phones and pushing the next set of new apps and new features to keep people addicted to their screens and keep them paying large monthly fees for higher-end subscriptions than they actually need.
How much longer until we see Dwayne Elizondo Mountain Dew Herbert Camacho on the presidential ballot?
Re: (Score:2)
Sure we can argue that out of all the airplane manufacturers and component suppliers, only Boeing 737s -- not including its 200 and 200-c series -- have manag
Re: (Score:2)
A few things you bring up:
1) Why did the Boeing purchase radar altimeters that were so easy to interfere with? Regardless of 5G, that seems like a safety risk.
2) Is this theoretical or actual? Like, 5G supports multiple frequencies. Are the ones that the cell phone companies want to use the same ones that the radar altimeters are susceptible to? Or is this only happening in a lab setting? (Still worth fixing though.)
3)
How much longer until we see Dwayne Elizondo Mountain Dew Herbert Camacho on the presidential ballot?
Whoever dares to change their name to that and run for president will likely be an o
Re: (Score:2)
Boeing's radar altimeters were plenty safe, until you start broadcasting with high power in a newly allocated nearby frequency band.
Re: (Score:2)
According to the article, the 5G signals they are worried about top-out at 3.98Ghz:
due to interference with radio altimeters from wireless broadband operations in the 3.7-3.98 GHz frequency band (5G C-Band).
According to the FAA [aviationtoday.com]
Aircraft radar altimeters operate within 4.2–4.4 GHz
Is 200Mhz not enough space?
The US sold that spectrum (Score:2)
If it wasn't safe to use for 5G then why did the US sell it with the express purpose of using it for 5G?
Either the FCC fucked up or the FAA fucked up. Given their recent history, I'd guess the latter.
Re: (Score:2)
"If they were important they would have been built to not fail when flying over a TV or radio transmitter tower."
They don't. But they might fail when flying over an American (but not a European) 5G transmitter. Those didn't exist when these radars were designed, bought and installed.
"Alas, the stray RF from a sneeze can, as the FAA claims, make planes fall out of the sky."
I very much doubt the FAA said any such thing. Translation, you're making this up.
You had one job (Score:2)
If only there was a government agency charged with allocating radio spectrum to prevent interference this wouldn't have happened.
Planes and cellphones in Europe work fine (Score:2)
Seems that the real problems are that in the US: ...with a side order of:
1) Cell phones can use a higher range of frequencies for 5G than in Europe: they use 3.4-3.8GHz, but in the US they are allowed to use up to 3.98GHz, which is closer to the 4.2 lower end of the radio altimeter spectrum.
2) Cell tower radio strength is something like 2.5x more than the average used in Europe.
3) The filters in some US planes may not have been very good?
The FCC decided that 1 & 2 are ok as far as they are concerned, an
Except the 200 series planes? (Score:2)
Re: (Score:2)
The altimeters worked fine until the FCC decided to allocate a nearby frequency band to 5G. The altimeters also continue to work fine with the European 5G, which uses a different frequency band, and which also employs other technologies to prevent interference with aircraft.
In other words, the US FCC botched it.