US Sets 2024 Deadline For 5G Signal Safeguards On Aircraft (bloomberg.com) 49
US aviation safety regulators intend to require passenger and cargo aircraft to meet requirements by early next year for navigation gear to deal with potentially unsafe interference from 5G mobile-phone signals. Bloomberg reports: The equipment is needed because the newer wireless signals are on frequencies near those used by planes' radio altimeters, which determine altitude over ground and can cause them to malfunction, the Federal Aviation Administration has found. Wireless companies are eager for a solution because they paid the government more than $80 billion for the new airwaves. The changes would need to be made by Feb. 1, 2024, the agency said in a notice (PDF) Monday.
The FAA said it couldn't rule out interference from 5G signals for about 100 incidents of aircraft navigation equipment issuing erroneous data. Such situations will increase as telecommunications providers expand 5G coverage throughout the US, the FAA said. [...] The FAA estimates that out of 7,993 US-registered aircraft that would need revisions, approximately 180 would require radio altimeter replacements and 820 would require the addition of filters to comply with the proposed order, at an estimated cost of as much as $26 million.
The FAA said it couldn't rule out interference from 5G signals for about 100 incidents of aircraft navigation equipment issuing erroneous data. Such situations will increase as telecommunications providers expand 5G coverage throughout the US, the FAA said. [...] The FAA estimates that out of 7,993 US-registered aircraft that would need revisions, approximately 180 would require radio altimeter replacements and 820 would require the addition of filters to comply with the proposed order, at an estimated cost of as much as $26 million.
Trolling the Trump Followers (Score:1)
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I wonder if (Score:1)
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Yes. The FAA did it’s own studies once the problem was posited. Only a handful of radio altimeters were affected in practice. Those are the focus of this rule.
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The FAA should ground the aircraft, or switch them to GPS altimeters until their receivers can be fixed. The 5G operators have the exclusive right to that spectrum, and should not be expected to hold back
Re:I wonder if (Score:4, Informative)
The RALTs are not "tuned" to those frequencies, but sensitive to those frequencies. It wasn't a big deal when those frequencies we're only used for satellite-to-earth-station downlinks, because planes didn't see those signals at powers comparable to the RALT power. When FCC changed the spectrum assignment for that band (adjacent to RALT spectrum) to 5G tower downlinks, it meant planes would see signals that were billions of times more powerful in that spectrum than they would under the old rules, so filters that were good enough before no longer were good enough.
https://www.rtca.org/news/rtca... [rtca.org] links to a white paper that goes into lots of detail about how the affected RALT filters behave. https://en.wikipedia.org/wiki/... [wikipedia.org] is the relevant factor for the receive filter; a filter with a lower Q factor is simpler and therefore (all else being equal) probably safer than one with a high Q factor.
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It boggles my mind that the FAA has found an issue with the altimeters and are allowing the planes to operate until 2024.
Why? The issue is only a concern during landing, not during flight, so it's only relevant in the immediate vicinity of airports. Towards that end, the government and telecoms have reached a temporary agreement to hold off on the deployment of 5G towers in the vicinity of airports. It doesn't stop the telecoms from rolling out nationwide 5G, other than around airports, so they can still do the bulk of the rollout they want to do. Airports tend to be surrounded by lower population density (because no one want
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Not just documentation or books, but a whole ITU standard governing the acceptable levels of interference both in and out of band for RAs. That's how this entire thing started, someone ran various 5G assignments in different countries through a computer simulator and identified they breached the ITU standard's requirements.
Who pays? (Score:3)
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Not this. All these receivers meet the standards they were designed to and the standards accepted by the FAA and FCC. Both the equipment and the ITU standard governing them predate the government's spectrum auction. The government's spectrum auction is in breach of the standard, not the other way around.
The fact that some RAs exceed the requirements of the standard doesn't mean the ones that meet the requirements shouldn't have been approved. That's not how any of this works.
Re:Who pays? (Score:4, Informative)
Truly, spoken like somebody who has never even learned the first thing about filter design, radio frequency electronics, avionic design processes or the relevant spectrum allocations!
There has always been a buffer within the RALT spectrum allocation. But the signals on the other side of that buffer are now billions of times (IIRC, 14 orders of magnitude, so almost a quadrillion times) more powerful than before. It's not surprising that real world filters stop being sufficient with that much more power to block, because real world filters have tradeoffs that the imaginary filters in your head don't have.
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Why should they? The airlines and manufacturers didn't properly manufacture their instruments to work with nearby interference.
Yes they did. 100% of the equipment is in compliance with the ITU standard for RAs. It was the government's frequency assignment which is not. RAs came first and so did the ITU standard governing them.
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How so? You can manufacture them properly, pass all required FCC interference tests, and then fail when suddenly a new user of a frequency band ramps up power an order of magnitude higher than was previously allowed. Previously those bands used by 5G were seldom used and used at only lower power. So yes, you can have a great design and then suddenly find problems when it is now in a new an unexpected environment and now need retrofitting.
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No, the devices are faulty, the use of other spectrum (however close and despite whatever it was used for before) should not have affected anything, but these devices are affected and thus are faulty.
Just because the devices have got away with it so far doesnt mean they arent at fault.
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No, the devices are faulty, the use of other spectrum
No they aren't. They don't use any other spectrum. They are susceptible to interference from other spectrum and that is part of their design, and a design governed by ITU standards, and also the reason why the bands either side of the in band spectrum was kept for sufficiently low powered devices.
The government themselves shat on the ITU standard, the hardware isn't at fault.
It's like me coming up and pouring sugar in your gas tank and then saying your car is faulty because it couldn't run with sugar in the
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I think people are applying some sort of software mentality to an RF problem, in that if there's a "bug" now then it should have been apparent in the past. Everyone doing RF design though knows particular bands are used only for particular purposes, and if suddenly there's a whole lot of noise in some guard bands that someone is breaking the rules. This particular problem is not a fault in design, but a fault of the rules of the road being broken. But this is slashdot, people will just pontificate here on
How much is a bandpass filter (SAW) (Score:3)
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Can't see how much a simple aviation band altimeter filter would retail at.
It's not a question of filtering. RAs work by measuring a signal they send. They are designed to produce a certain signal and expect a certain signal in return. Filtering out part of that signal causes a significant increase in measurement error. You can't just throw a filter in, you need to replace the entire unit (or at least the transceiver including amplifiers, antennas, and yes filters too).
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A SAW filter would not have remotely good enough performance at 4.2 GHz to pass enough of the desired signal while attenuating the adjacent signal (at up to 3.98 GHz nominal) by towards of 100 dB. Do you know how many dB per octave that equates to?
Also, the RALTs typically work at a relatively wide bandwidth in order to get good ranging precision. A receiver with 20 MHz bandwidth probably won't be able to receive the altitude signal very well, even if equipped with an antenna sensitive enough to receive t
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Aviation is a very conservative. Change for the sake of chan
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And what if ... (Score:4, Interesting)
It's not just the older equipment. Manufacturers of state of the art radio altimeters like Garmin [garmin.com] have expressed concern over the interference issue. And it's not just a problem near airports. RAs are used by helicopters for instrument flight rules. So that means a 5G tower might prevent air medical services from operating, possibly resulting in deaths.
Perhaps the government should just hand the wireless companies their 80 billion dollars back and say "Sorry. It was just a big mistake."
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Re:And what if ... (Score:4, Insightful)
Without looking it up, do you even know what the biggest concerns are about using GPS as a replacement for this, or are you just shooting off your ignorant mouth? Do you know what an approach plate is? PBN versus PA? VPL versus VPE versus OCS? What "out-of-band operations" means and why it's inaccurate in this case?
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The aircraft can use GPS
Oh my sweet summer child. Tell us you don't know anything about aircraft electronics without telling us you don't know anything about aircraft electronics.
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GPS isn't always available depending on where you are. It can be blocked or jammed. It's an amazing thing and it's there most of the time, but not all.
It also isn't what planes use to maintain separation. They use indicated altitude, which I believe is the barometric altitude corrected for local weather conditions.
In the best case, planes have several different mechanisms to measure altitude. (Barometric and radio are the main ones.) But they all can fail. The combination of multiple systems, processe
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It's for upscale cellular phone users. The faulty equipment in this case is are the 5G users, not the altimeters which were designed under the rules that these bands would not be used except for some low power satellite comms. The rules were broken here when those bands were sold off, plain and simple.
Nothingburger (Score:1)
This is just a waste of air.
There's no interference, but there sure is a lot of hype.
Europe - useless regulation-happy monkeys have it right.
US FAA - still can't get it right.
US FCC - can't even get their board elected..
Useless elected piece of shit moving their lips and contributing NOTHING to passenger safety.
So noise shielding is difficult now? (Score:1)
Since when was it difficult to shield signal cables from noise?
Srsly, shielded twisted-pair cables have existed since forever, not to mention current-loop. Just look an MIDI cables.
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The problem supposedly used to be something about the internal signalling between the components inside the plane. That's where the shielding comes in, as well as balancing the signal/ground cables etc.
But yeah, radio transceivers are another matter. If their frequency ranges start fighting with civvie phones and wifi etc, then we do have a problem.
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That is the problem as I understand it.
From what I understand, internal cabling is well-shielded already, at least where it needs to be.
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No, the problem was always adjacent channel interference through the RALT antenna. Coupling into cables is not even why cell phones are supposed to be in airplane mode when the plane is running -- it's because a ton of systems on the plane use RF and don't want a hundred or so phones figuratively screaming "hey, cell tower, can you hear me?" close to GPS L1 or whatever other frequencies they are using.
I linked to an RTCA white paper up-thread that does a detailed analysis of many potential sources of inter
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So, if I'm understanding this right, the problem is twofold: GPS insists on stuffing LF components into their transmissions, and electric equipment all over the place isn't properly shielded against crap like that. Old problem, not exactly exclusive to planes. Hence my original post.
On top of that, GPS frequencies muck with RF stuff, like radars. Especially on planes. Which is where s*t gets serious.
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No, you don't understand it correctly. Thanks for posting.
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Are you saying GPS doesn't disrupt unshielded cabled connections?
Or are you saying it doesn't disrupt radars and radio connections? Like, plane radars?
If so, then what was this entire thread all about?
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This thread is about 5G radios, not GPS.
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It never means that. 5G is the fifth generation of mobile telephony. GPS (the Global Positioning System, operated by the USA) is currently launching "Block III" satellites, although Block II had five versions with some significant additions along the way.
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