5G’s Rollout Rattled Hundreds of Pilots(spectrum.ieee.org)
spectrum.ieee.org
5G’s Rollout Rattled Hundreds of Pilots
https://spectrum.ieee.org/faa-5g
118 comments
> FAA for making this process difficult- see 737 certification as an example, leading to the max accidents.
The certification process being "difficult" isn't why the 737 Max was unsafe. The FAA allowed Boeing to self-certify its safety, and voices inside the company were ignored or silence. They literally created a system to save a buck for their clients then outsourced development of that system to save another buck, then rubber-stamped it themselves.
Blaming this on too much or too difficult regulation is farcical.
PS - I also find the entire thrust of this argument contradictory: "Equipment built in the 80s wasn't high enough quality for the new 5G operating environment, so we need to weaken 'difficult' regulation today to make producing lower quality equipment cheaper, tomorrow be damned."
The certification process being "difficult" isn't why the 737 Max was unsafe. The FAA allowed Boeing to self-certify its safety, and voices inside the company were ignored or silence. They literally created a system to save a buck for their clients then outsourced development of that system to save another buck, then rubber-stamped it themselves.
Blaming this on too much or too difficult regulation is farcical.
PS - I also find the entire thrust of this argument contradictory: "Equipment built in the 80s wasn't high enough quality for the new 5G operating environment, so we need to weaken 'difficult' regulation today to make producing lower quality equipment cheaper, tomorrow be damned."
Going through the process to type certify the Max as anything other than a 737 would’ve been far more expensive, slow and painful for Boeing and all its customers because of how slow and difficult the FAA is.
They added the MCAS because they didn’t want the Max to be a different type, which meant starting the certification process from scratch. They were able to self certify precisely because it was a 737 type.
Yes - there were many issues that lead to the accidents and you can’t really point to just the one thing; but ultimately it did boil down to a culture at the company created by the environment it operates under.
I’m not defending Boeing here - if anything, I’m more upset at them as they had the engineering will and talent, the political and financial backing to make meaningful changes to the regulatory environment and make aviation safer as a manufacturer - but they chose greed.
Lastly, that’s nowhere near what I said but I can see how you can get to that conclusion. I’m an aviation enthusiast and a Pilot (feel free to go through my post history) - and it’s not a question of weakening regulation; it’s a matter of streamlining ways to get new technology certified faster - it only took 3 decades for the FAA to give the STC for unleaded gasoline etc etc.
They added the MCAS because they didn’t want the Max to be a different type, which meant starting the certification process from scratch. They were able to self certify precisely because it was a 737 type.
Yes - there were many issues that lead to the accidents and you can’t really point to just the one thing; but ultimately it did boil down to a culture at the company created by the environment it operates under.
I’m not defending Boeing here - if anything, I’m more upset at them as they had the engineering will and talent, the political and financial backing to make meaningful changes to the regulatory environment and make aviation safer as a manufacturer - but they chose greed.
Lastly, that’s nowhere near what I said but I can see how you can get to that conclusion. I’m an aviation enthusiast and a Pilot (feel free to go through my post history) - and it’s not a question of weakening regulation; it’s a matter of streamlining ways to get new technology certified faster - it only took 3 decades for the FAA to give the STC for unleaded gasoline etc etc.
I'm pretty sure the reason that Boeing didn't want to certify the Max as anything other than a 737 is that this would have required expensive pilot-retraining for all airlines purchasing that aircraft, and this would have put Boeing in a bad position relative to Airbus, with the main factor being 'fuel burn per seat' where the Airbus A320neo had an initial advantage. The plane designs are nicely compared here (2014), esp. Fig 2:
https://seekingalpha.com/article/2765285-the-battle-on-the-n...
The shoddy software primarily responsible for the Boeing 737MAX disasters was introduced so that Boeing could market the planes to airlines as a standard 737 that required no expensive pilot training programs, as far as I can tell. The nature of the FAA's regulatory process seems mostly irrelevant here, unless rushing poorly designed products with huge risk profiles to market to help Boeing improve sales is something the FAA should promote... note also that Boeing lost around $30 billion in market value over the MAX debacle, which could have been avoided by FAA being more strict, even if that mean fewer plane orders.
https://seekingalpha.com/article/2765285-the-battle-on-the-n...
The shoddy software primarily responsible for the Boeing 737MAX disasters was introduced so that Boeing could market the planes to airlines as a standard 737 that required no expensive pilot training programs, as far as I can tell. The nature of the FAA's regulatory process seems mostly irrelevant here, unless rushing poorly designed products with huge risk profiles to market to help Boeing improve sales is something the FAA should promote... note also that Boeing lost around $30 billion in market value over the MAX debacle, which could have been avoided by FAA being more strict, even if that mean fewer plane orders.
you are 100% correct about retraining. Flying Blind is a great book about the MAX failures at both Boeing and the FAA that I just finished a few weeks ago, highly recommend.
Just to add a bit to this, as far as I understand, they didn't want the Max to be certified as something other than a normal 737, not because of certifying the aircraft, but because it would also mean all pilots would need additional training or even new type ratings to fly it.
Though, adding the MCAS, which in certain circumstances overrides the pilots instructions, should most certainly have triggered new training for the pilots for those situations, at the very least.
Though, adding the MCAS, which in certain circumstances overrides the pilots instructions, should most certainly have triggered new training for the pilots for those situations, at the very least.
> Going through the process to type certify the Max as anything other than a 737 would’ve been far more expensive
Nonsense. Boeing regularly does that.
> They added the MCAS because they didn’t want the Max to be a different type, which meant starting the certification process from scratch.
Also nonsense.
They added the MCAS because they didn’t want the Max to certify as anything but a different type because the entire point of the Max program was for customers who exclusively fly 737s (like Southwest) to be able to fly a more efficient plane without needing to recertify pilots.
Unlike Airbus, Boeing does not have unified profiles and accelerated cross-type training[0], so changing type is close to a full certification for crews, which translates to the crews being grounded for several weeks / a few months.
[0] IIRC they have something along those lines for some planes released close to one another, but Airbus has it across most of the range, with the exception of the older types and the A220 which is not an Airbus plane per-se (it's a rebadging of the Bombardier CSeries)
Nonsense. Boeing regularly does that.
> They added the MCAS because they didn’t want the Max to be a different type, which meant starting the certification process from scratch.
Also nonsense.
They added the MCAS because they didn’t want the Max to certify as anything but a different type because the entire point of the Max program was for customers who exclusively fly 737s (like Southwest) to be able to fly a more efficient plane without needing to recertify pilots.
Unlike Airbus, Boeing does not have unified profiles and accelerated cross-type training[0], so changing type is close to a full certification for crews, which translates to the crews being grounded for several weeks / a few months.
[0] IIRC they have something along those lines for some planes released close to one another, but Airbus has it across most of the range, with the exception of the older types and the A220 which is not an Airbus plane per-se (it's a rebadging of the Bombardier CSeries)
Regulation has more than one dimension.
We are not limited to talking about 'weakening' or 'strengthening' regulations. We can talk about making saner rules, too.
We are not limited to talking about 'weakening' or 'strengthening' regulations. We can talk about making saner rules, too.
> PS - I also find the entire thrust of this argument contradictory: "Equipment built in the 80s wasn't high enough quality for the new 5G operating environment, so we need to weaken 'difficult' regulation today to make producing lower quality equipment cheaper, tomorrow be damned."
No, the problem is that the altimeters didn't meet spec.
These altimeters are NOT supposed to be susceptible to these frequencies. However, people cut corners decades ago and now it's being found out.
The FAA should have told the airlines "You have N years to get these replaced. Start now." But they didn't--because they're in the pocket of the big aerospace companies.
Well, so the FCC rolled it out. Now the FAA and the aerospace companies have to deal with it.
No, the problem is that the altimeters didn't meet spec.
These altimeters are NOT supposed to be susceptible to these frequencies. However, people cut corners decades ago and now it's being found out.
The FAA should have told the airlines "You have N years to get these replaced. Start now." But they didn't--because they're in the pocket of the big aerospace companies.
Well, so the FCC rolled it out. Now the FAA and the aerospace companies have to deal with it.
[deleted]
No, blame the FCC for not properly clearing frequencies used by safety-critical equipment before reassigning them to 5G. They wanted to stick cellphones right next to altimeters, it should be their burden to make sure all the altimeters currently deployed won't get hit with sideband noise.
The FAA's approach is reasonable because safety-critical equipment is, well, critical to safety. The FCC got rolled by the 5G hype train and failed to do its job - i.e. allocate frequencies to avoid unintended interference.
The FAA's approach is reasonable because safety-critical equipment is, well, critical to safety. The FCC got rolled by the 5G hype train and failed to do its job - i.e. allocate frequencies to avoid unintended interference.
Sorry, but no.
It's 220mhz away.
That's insane. No properly operating equipment needs that sort of gap, and certainly not radar altimeters built with the proper selectivity.
This is a 100% solved problem, and a 100% failure on the part of the equipment manufacturers, and whatever certification procedures exist for them.
It simply is not that hard to test this, certify this, etc.
That's insane. No properly operating equipment needs that sort of gap, and certainly not radar altimeters built with the proper selectivity.
This is a 100% solved problem, and a 100% failure on the part of the equipment manufacturers, and whatever certification procedures exist for them.
It simply is not that hard to test this, certify this, etc.
there is a 220MHz buffer between the two bands. that's eleven (11) terrestrial commercial FM radio bands worth of gap.
220MHz is sufficient if your altimeter radar has the proper selectivity.
ground radars are so selective that you can have two radar devices operating at the same frequency aimed at each other without interference.
220MHz is sufficient if your altimeter radar has the proper selectivity.
ground radars are so selective that you can have two radar devices operating at the same frequency aimed at each other without interference.
Sorry? Would you mind explaining that for a layman?
How do two devices on the same frequency, pointing at each other, not interfere?
How do two devices on the same frequency, pointing at each other, not interfere?
because they look for reflected signals, which changes how the waveform is shaped, and there is circuitry which ignores unreflected inputs.
additionally, the radars sweep through their bands rather than broadcast on all of it at once, so the chance of them looking for the frequency that the other radar is sending at the exact moment it is being sent is very small, and when it does happen it is easily ignored.
the sweeping is what provides the ability to easily detect movement and change in distance from radar to target.
this is all based on a book I read years ago, so I apologize if any of it is not exactly on the dot accurate.
additionally, the radars sweep through their bands rather than broadcast on all of it at once, so the chance of them looking for the frequency that the other radar is sending at the exact moment it is being sent is very small, and when it does happen it is easily ignored.
the sweeping is what provides the ability to easily detect movement and change in distance from radar to target.
this is all based on a book I read years ago, so I apologize if any of it is not exactly on the dot accurate.
Hey that's great, thankyou - even if it's not 100% you've given me a leg up to start looking into it further some rainy afternoon.
This is just as much the FCCs fault as the FAA. They were the ones that certified the frequency usage of these altimeters, and they should have noticed that these altimeters could experience interference from satcom frequencies over 400MHz (!!!) away. They could have stopped this decades ago, but they let it go on long enough to become a massive problem.
A lot of people don't seem to grasp the magnitude of the spectrum lost to this snafu. At today's realizable spectral efficiencies, that is 2.5 TB/s of usable data throughput lost to the 400MHz guard band alone. It's also ~$130B worth of revenue that the FCC could have had if they could actually sell it.
A lot of people don't seem to grasp the magnitude of the spectrum lost to this snafu. At today's realizable spectral efficiencies, that is 2.5 TB/s of usable data throughput lost to the 400MHz guard band alone. It's also ~$130B worth of revenue that the FCC could have had if they could actually sell it.
The problem here was sort of ideal for falling through the cracks.
The FAA is an executive administration ultimately organized under Dept. of Transportation. The FCC is an independent executive agency overseen, ultimately, by Congress.
As a result, neither org has unilateral authority to tell the other to go pound sand, nor do their up-org leadership (ultimately, the President v. Congress).
Their inability to find a resolution that didn't leave American pilots floundering is reflective of the inability of the Legislative and Executive branches to work together in modern federal governance, in general. Expect more issues like this in the future.
The FAA is an executive administration ultimately organized under Dept. of Transportation. The FCC is an independent executive agency overseen, ultimately, by Congress.
As a result, neither org has unilateral authority to tell the other to go pound sand, nor do their up-org leadership (ultimately, the President v. Congress).
Their inability to find a resolution that didn't leave American pilots floundering is reflective of the inability of the Legislative and Executive branches to work together in modern federal governance, in general. Expect more issues like this in the future.
Sure, the receivers could experience interference from satcom frequencies in theory, but in practice satcom broadcasts are very low strength, so there was not much risk of harmful interference until the frequency was repurposed for terrestrial, high power broadcasts.
You don't put hurricane windows on buildings that have no hurricane risk, and you don't put tight bandpass filters on receivers in the satellite bands.
When hurricane patterns or satellite bands change, you get problems though.
You don't put hurricane windows on buildings that have no hurricane risk, and you don't put tight bandpass filters on receivers in the satellite bands.
When hurricane patterns or satellite bands change, you get problems though.
Satcom downlinks might be low power, but uplinks, especially from dedicated base stations (as opposed to satellite phones) can easily run into the hundreds of watts.
We enjoy accessible and safe air travel in no small part due to the strict regulations by FAA and EASA.
Aviation is an industry where new products absolutely should not be fast tracked into deployment. The rules and regulations that are in place today were written in blood.
If anything it's the weakening of these regulations (i.e. manufacturer self-certification) that enabled the MAX disasters.
Aviation is an industry where new products absolutely should not be fast tracked into deployment. The rules and regulations that are in place today were written in blood.
If anything it's the weakening of these regulations (i.e. manufacturer self-certification) that enabled the MAX disasters.
The FAA being archaic was absolutely not the cause of the MAX incidents. Boeing released a plane with a single point of failure that failed, and they also neglected to tell pilots and FAA about this single point of failure because pilots unions would have insisted on training in a simulator (which costs Boeing money) and the FAA may have insisted on a redesign or also simulator training.
Your comment is a complete mischaracterization of the MAX incidents beyond what even Boeing public relations was willing to do.
Your comment is a complete mischaracterization of the MAX incidents beyond what even Boeing public relations was willing to do.
[deleted]
It's relevant, at least.
The single point of failure was a bad implementation detail of a bad feature, and that feature mostly existed because of how all-or-nothing the "aircraft type" training is.
The single point of failure was a bad implementation detail of a bad feature, and that feature mostly existed because of how all-or-nothing the "aircraft type" training is.
It doesn't matter how easy the new certification process is, or how the technical specification said it _should_ have worked; this was existing technology that was otherwise working. You can't come in and step on existing infrastructure, then declare ex post facto that it should have gotten out of the way before you got there.
Cat IIIc landings are no joke.
https://www.aopa.org/news-and-media/all-news/2019/september/...
https://www.aopa.org/news-and-media/all-news/2019/september/...
The rollout of this was disgusting.
The FCC only cared about selling the spectrum.
The FAA only cared about minimizing the chance of any accidents.
Neither was able to look at the science, come to a compromise, and then implement it in a joint way. It took the carriers, who had just paid $80b (from the article) to inject sanity into the approach via voluntary buffer zones.
Turns out, single purpose regulatory agencies aren't great at considering matters outside their area of focus...
The FCC only cared about selling the spectrum.
The FAA only cared about minimizing the chance of any accidents.
Neither was able to look at the science, come to a compromise, and then implement it in a joint way. It took the carriers, who had just paid $80b (from the article) to inject sanity into the approach via voluntary buffer zones.
Turns out, single purpose regulatory agencies aren't great at considering matters outside their area of focus...
It seems like this is a case of multi-agency regulatory capture (by industries with competing interests) resulting in behavior akin to a failed state. If the state can’t arbitrate conflicts over public goods, what good is it?
> If the state can’t arbitrate conflicts over public goods, what good is it?
It could. Did anyone bring it to a court?
It could. Did anyone bring it to a court?
Is the only way for the fcc and faa to come to a joint conclusion for someone to spend millions in court forcing them to?
Did I say that? Or am I responding to a extremely bizarre comment about the US being a “failed state” when parties found a solution without even exhausting the most obvious answer (given the US is a lawsuit-happy nation)
would it be really surprising if that was the case though?
If all the FAA cared about was minimizing the chance of accidents, then surely they would have fast-tracked the certification and rollout of better radar altimeters that can operate in the spectrum allotted to them?
This seems like a case of the FAA's "never change a running system" running into a world that is changing. A world that expects radio equipment to be better behaved than the stuff we built in the 80s.
This seems like a case of the FAA's "never change a running system" running into a world that is changing. A world that expects radio equipment to be better behaved than the stuff we built in the 80s.
By FAA accounting, no change is less risky than any change.
And given their track record of success and reality, I partially understand. The only way to avoid unknown unknowns is to maximally simplify a system, and that starts with not introducing components uncharacterized by decades of real world use.
Obvious parallel in tech: database systems.
And given their track record of success and reality, I partially understand. The only way to avoid unknown unknowns is to maximally simplify a system, and that starts with not introducing components uncharacterized by decades of real world use.
Obvious parallel in tech: database systems.
In a world where nothing changes, or at least doesn't change without an impact assessment by the FAA, they are kind of right.
The problem is that aircraft inhabit the same world as the rest of us, so sometimes their environment does change from things outside FAA control. And at that point, delaying technology updates for nearly half a century becomes a major liability.
The problem is that aircraft inhabit the same world as the rest of us, so sometimes their environment does change from things outside FAA control. And at that point, delaying technology updates for nearly half a century becomes a major liability.
> The FAA only cared about minimizing the chance of any accidents.
I think this is a good thing.
I think this is a good thing.
No flying guarantees no accidents. This creates incentives in the wrong direction.
See for example the safety achieved by modern technologies in modern light aircraft designs, and the lack of certification of most of these because of the expense of complying with FAA certification requirements. So the certified fleet has to use existing certified designs from the 60s which have not progressed as much in safety.
See for example the safety achieved by modern technologies in modern light aircraft designs, and the lack of certification of most of these because of the expense of complying with FAA certification requirements. So the certified fleet has to use existing certified designs from the 60s which have not progressed as much in safety.
You have a point about the FAA's handling of potentially safety-enhancing new technology, but that is not the issue here. Its safety concerns were verified by events after the compromise was put into effect (and the absence of any accidents as a consequence is not a counter-argument.)
The root cause of this problem is, to an extent, a problem of agency silos. The FCC exercised its responsibility for controlling radio interference almost entirely by regulating what equipment can transmit, but radar altimeters are now giving false readings because they are overly sensitive to signals they receive outside of their allotted bands. While this may formally be part of the FCC's responsibility, it is clearly something the FAA could have been more concerned about.
The root cause of this problem is, to an extent, a problem of agency silos. The FCC exercised its responsibility for controlling radio interference almost entirely by regulating what equipment can transmit, but radar altimeters are now giving false readings because they are overly sensitive to signals they receive outside of their allotted bands. While this may formally be part of the FCC's responsibility, it is clearly something the FAA could have been more concerned about.
That appears to be the stance of the NRC(Nuclear Regulatory Commission) as well.
Let's see, one party focus on safety (minimizing the chance of accidents) and the other focises on revenue. I know which of the parties has more legs to stand upon. And don't pull out the MAX disaster, that is the proverbial exception that proofs the rule.
You can call it focusing on revenue if you want, but the reason carriers are willing to pay so much for it is because it is so useful. The 280MHz of C-Band spectrum is close to 2TB/s of data throughput. That is a massive benefit to our society.
If we only cared about safety, zero planes would be in the air right now. But sometimes usefulness outweighs safety.
And the money-grubber argument could easily go both ways. The airlines bought radar altimeters that were out of spec. They could buy radar altimeters that are in spec and just as safe, but that would cost money. You could just as easily spin that as the FAA only caring about money.
If we only cared about safety, zero planes would be in the air right now. But sometimes usefulness outweighs safety.
And the money-grubber argument could easily go both ways. The airlines bought radar altimeters that were out of spec. They could buy radar altimeters that are in spec and just as safe, but that would cost money. You could just as easily spin that as the FAA only caring about money.
The FAA isn't hetting money from manufacturers for certification taking longer. Altimeters out of spec are, if true, a no-go and finding for every continued airworthiness org out there.
What interests would you want to see represented here other than minimizing the chance of accidents?
Well the concept of efficiency should be represented, financial responsibility, technological innovation, consumer and general public requirements, and then alongside this working collaboratively with other agencies to create joined-up policy (which involves balance between the needs of both agencies).
Sure but all of those come after the safety thing, right? We wouldn't want the most cost effective and innovative option to be chosen if it's unsafe?
Safety isn't binary.
The only way to achieve total aircraft safety is to have no aircraft. If the FAA literally cared about nothing other than safety they would have everything grounded, so clearly they do to some extent care about other things.
Plausibly, a well-designed government would be explicit about the tradeoffs between safety and convenience and cost and so forth. In practice, that might be politically catastrophic. What usually happens, I think, is something like this: the official line is "keep risk down to a negligible level", where "negligible" is usually not quantified, and cost/inconvenience is largely ignored until everyone agrees that the risk has been made negligible, but below that threshold everyone's free to minimize cost/inconvenience.
(This might actually end up being a pretty good strategy. Let's measure cost and convenience in dollars, because trading those off against one another isn't so problematic; then maybe a reasonable approximation to what we care about is that 1. each death is like burning $X where X is probably some number of millions, and 2. having any major accident in a given year is like burning $Y where Y is many billions, because if there's a major accident then the hit to public confidence means (a) big loss to the airline industry, (b) more people driving instead of flying, which means more deaths because flying is much safer, and wasting a lot of their time, and probably also more environmental damage. In that case, maybe the effect of #2 is actually not so very different from "big penalty if the risk goes above a negligible level". But it seems like we'd get better decisions overall by being more explicit about what we care about and how much.)
The only way to achieve total aircraft safety is to have no aircraft. If the FAA literally cared about nothing other than safety they would have everything grounded, so clearly they do to some extent care about other things.
Plausibly, a well-designed government would be explicit about the tradeoffs between safety and convenience and cost and so forth. In practice, that might be politically catastrophic. What usually happens, I think, is something like this: the official line is "keep risk down to a negligible level", where "negligible" is usually not quantified, and cost/inconvenience is largely ignored until everyone agrees that the risk has been made negligible, but below that threshold everyone's free to minimize cost/inconvenience.
(This might actually end up being a pretty good strategy. Let's measure cost and convenience in dollars, because trading those off against one another isn't so problematic; then maybe a reasonable approximation to what we care about is that 1. each death is like burning $X where X is probably some number of millions, and 2. having any major accident in a given year is like burning $Y where Y is many billions, because if there's a major accident then the hit to public confidence means (a) big loss to the airline industry, (b) more people driving instead of flying, which means more deaths because flying is much safer, and wasting a lot of their time, and probably also more environmental damage. In that case, maybe the effect of #2 is actually not so very different from "big penalty if the risk goes above a negligible level". But it seems like we'd get better decisions overall by being more explicit about what we care about and how much.)
The approach I think you are proposing, safety above all, often leads to very low efficiency and in the end can lower total safety, for example encouraging shift to alternative modes of transport. Or by setting the certification bar so high that companies with new technologies, including those to improve safety, do not even bother to apply.
An approach of joint utility, taking into account time, money and risk usually works better.
An approach of joint utility, taking into account time, money and risk usually works better.
So you weigh the importance of Verizon Wireless’s ability to compete with TMobile for midband 5G equally with risk to human life?
Give me a break.
Give me a break.
Not equally (where did I say that?) but put frankly it depends how much risk.
Everything is a trade-off, and actually what we usually aim to do as society is to manage acceptable and balanced levels of risk rather than use safety as the single-lens to make decision. As an example, the design of cars would be very different if they were designed only with safety in mind, and if automakers pursued this goal ignoring factors such as speed, comfort and price point (or indeed, competitive pressures).
It's also worth noting that the "efficiency" in my post actually came from the stated goals of the FAA.
Everything is a trade-off, and actually what we usually aim to do as society is to manage acceptable and balanced levels of risk rather than use safety as the single-lens to make decision. As an example, the design of cars would be very different if they were designed only with safety in mind, and if automakers pursued this goal ignoring factors such as speed, comfort and price point (or indeed, competitive pressures).
It's also worth noting that the "efficiency" in my post actually came from the stated goals of the FAA.
FAA is dual mandate though which is really a significant barrier to effectiveness in either sector.
It is important to note that 5G and aircraft radar altimeters do NOT operate or coexist on the same frequencies. The problem is that 5G frequencies are close to radar altimeter c-band frequencies and the issue lies with certain aircraft that do not have sufficient band pass filters in place on their radar altimeter receivers, so when a strong 5G signal is present the aircraft's radar altimeter can be overloaded with adjacent channel interference.
Retrofitting band pass filters on existing aircraft radar altimeters isn't a trivial task - avionics changes to aircraft are a multi-year project since extensive testing is done on anything electrical installed on an aicraft.
Additionally, some 5G infrastructure equipment may need additional band pass filters installed to prevent spurious transmissions outside of their assigned frequency ranges in areas near airports.
If you aren't familiar with a bandpass filter, it basically filters all RF outside of a certain frequency range. Sensitive receivers can naturally be overwhelmed by RF outside of the receiver's frequency range, and preventing that RF getting to the receiver in the first place is the role of a band pass filter.
Retrofitting band pass filters on existing aircraft radar altimeters isn't a trivial task - avionics changes to aircraft are a multi-year project since extensive testing is done on anything electrical installed on an aicraft.
Additionally, some 5G infrastructure equipment may need additional band pass filters installed to prevent spurious transmissions outside of their assigned frequency ranges in areas near airports.
If you aren't familiar with a bandpass filter, it basically filters all RF outside of a certain frequency range. Sensitive receivers can naturally be overwhelmed by RF outside of the receiver's frequency range, and preventing that RF getting to the receiver in the first place is the role of a band pass filter.
I’m not sure why so many things have gotten both fantastically more advanced and much worse at the same time. Reminds me of the “premium mediocre” conundrum a bit.
In this case we can see it’s not the usual suspect (over/efficiency mindset) but maybe there is something much uglier lurking underneath? Affecting both companies and government bodies even - which should feel less “budget” pressure to be overly efficient in everything?
I don’t know what factors those are. Though they could still be that plus something else (more transparently cultural)?
In this case we can see it’s not the usual suspect (over/efficiency mindset) but maybe there is something much uglier lurking underneath? Affecting both companies and government bodies even - which should feel less “budget” pressure to be overly efficient in everything?
I don’t know what factors those are. Though they could still be that plus something else (more transparently cultural)?
I don't think it's more complicated than money in either case.
Businesses are increasing consolidated and have market pressure to show not just profits but increasing profits year over year.
Government agencies are affected by a combination of regulatory capture and a half century of austerity
Businesses are increasing consolidated and have market pressure to show not just profits but increasing profits year over year.
Government agencies are affected by a combination of regulatory capture and a half century of austerity
> I don't think it's more complicated than money in either case.
The trick is to make it look more complicated than that, so no one follows the money. If somebody does, call them names. If calling them a Luddite conspiracy theorist doesn't work because you used to employ them as an expert and they have a long track record, just say that they're bolstering or emboldening or platforming Luddite conspiracy theorists (who might also be racist-adjacent China-deniers.)
You buy a media in order to use it.
The trick is to make it look more complicated than that, so no one follows the money. If somebody does, call them names. If calling them a Luddite conspiracy theorist doesn't work because you used to employ them as an expert and they have a long track record, just say that they're bolstering or emboldening or platforming Luddite conspiracy theorists (who might also be racist-adjacent China-deniers.)
You buy a media in order to use it.
Worth noting that, just like the meteorological disruption, this is a US-only problem. It's not a problem with 5G in general, other countries assigned safe bands instead.
Has 5g brought anything positive to this world? So much hype but all it seems to have done is make flying more unsafe, create more ugly towers in cities and discharge my phone faster. Seems like boondoggle territory to me.
Faster data rates, lower network congestion, more efficient spectrum allocation, and private commercial networks for IoT. There are many benefits. Although, perhaps marketing has oversold those benefits that will be passed into consumers. Largely, 5G will benefit network operators, carriers, and industry.
5G has not appreciably made “flying more unsafe.” If anything, this is a good push to start updating altimeters to spec (installing bandpass filters, better testing) which actually will make flying more safe because currently these altimeters are susceptible to out of band frequencies.
5G has not appreciably made “flying more unsafe.” If anything, this is a good push to start updating altimeters to spec (installing bandpass filters, better testing) which actually will make flying more safe because currently these altimeters are susceptible to out of band frequencies.
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I've learned that every time I'm near a city center and my phone loses connection or gets very slow, there's a little "5G" showing in the status bar.
Every damn time.
Sometimes I'm able to mess with the network settings to turn off 5G and go back to 4G, and then my phone works fine again.
Every damn time.
Sometimes I'm able to mess with the network settings to turn off 5G and go back to 4G, and then my phone works fine again.
It enables smart cities with more surveillance to keep us all safe.
Don't forget, it's impacted weather forecasting too.
Came here to say the same thing:
https://www.salon.com/2022/03/14/how-5g-could-send-weather-f...
The central issue here is greed. The bands used for science (like 23.8 GHz) are critical, but not enough concern was given to them, so neighboring bands were auctioned off without proper consideration of consequences from interference, due to lobbying pressure from telecommunications companies. From the article:
While the FCC's 2019 auction of the 24 GHz spectrum band generated $2 billion in revenue for the Department of the Treasury, the costs from severe weather could be much greater.
This is the type of unintended consequence that comes with privatization of government services. What looks like a cost savings in the short term ends up being a cost increase in the long term. See also: the commons, natural monopoly.
https://www.salon.com/2022/03/14/how-5g-could-send-weather-f...
The central issue here is greed. The bands used for science (like 23.8 GHz) are critical, but not enough concern was given to them, so neighboring bands were auctioned off without proper consideration of consequences from interference, due to lobbying pressure from telecommunications companies. From the article:
While the FCC's 2019 auction of the 24 GHz spectrum band generated $2 billion in revenue for the Department of the Treasury, the costs from severe weather could be much greater.
This is the type of unintended consequence that comes with privatization of government services. What looks like a cost savings in the short term ends up being a cost increase in the long term. See also: the commons, natural monopoly.
I find the airplane operators/pilot overentiteled. Why shut down 5G as some of them suggest if its the altimeters on the planes that are actually defective/not within spec.
>if its the altimeters on the planes that are actually defective/not within spec.
Is there any evidence this is the case? This sort of thing is a lot like property zoning. If a steel mill starts up next door to your residential property in what used to be a park then there is nothing stopping you from adding more sound proofing to your walls to make it so you can sleep. But should you have to do this and can you do this at all? In this case the neighbouring band was originally used for satellite downlinks. So barely detectable signals with large dishes required. Radar altimeters in aircraft actually used to cause interference to the satellite downlinks when the aircraft flew over.
The fact is that you need to have sufficient physical separation between services in adjacent bands. In this case, you can't expect things to work if an aircraft flies directly over a 4 GHz 5G transmitter at a low altitude. This aspect of adjacent band interference is an important part of spectrum management. You can't just wave the issue away...
Is there any evidence this is the case? This sort of thing is a lot like property zoning. If a steel mill starts up next door to your residential property in what used to be a park then there is nothing stopping you from adding more sound proofing to your walls to make it so you can sleep. But should you have to do this and can you do this at all? In this case the neighbouring band was originally used for satellite downlinks. So barely detectable signals with large dishes required. Radar altimeters in aircraft actually used to cause interference to the satellite downlinks when the aircraft flew over.
The fact is that you need to have sufficient physical separation between services in adjacent bands. In this case, you can't expect things to work if an aircraft flies directly over a 4 GHz 5G transmitter at a low altitude. This aspect of adjacent band interference is an important part of spectrum management. You can't just wave the issue away...
Altimeters are allowed to use the 4.2GHz - 4.4GHz band. They are getting interference from signals at 3.98GHz and below. This means they need over twice the spectrum that was allocated to them.
It's more like the family who is first to move into a neighborhood under construction, complaining that their kids can no longer play in the empty lots because houses are being built there. And it's not even the empty lot next to them, but one lot over.
It's more like the family who is first to move into a neighborhood under construction, complaining that their kids can no longer play in the empty lots because houses are being built there. And it's not even the empty lot next to them, but one lot over.
Filters are not magic. They have tradeoffs. If you make a filter with a really sharp cutoff you end up with a really large filter with a lot of loss. So then you have trouble receiving really weak signals, say, reflections from the ground. One way you might overcome this is to really ramp up the transmitted power but that can cause radar receiver problems and can cause interference with services in adjacent bands, say, 5G.
This sort of thing is why allocating TV frequencies is and was complicated. That is because someone might live right next door to a TV transmitter and they might be trying to watch a weak signal on an adjacent channel. You usually have to allocate some dead channels for the area to prevent receivers from being overloaded. So in that case would it be fair to say that receiver was using channels it had no right to when set to the weaker signal? After all, the transmitter was there before the receiver was...
Note that other countries have managed to deal with this routine and common issue with respect to the introduction of 4 GHz 5G. There is something weird going on in the USA...
This sort of thing is why allocating TV frequencies is and was complicated. That is because someone might live right next door to a TV transmitter and they might be trying to watch a weak signal on an adjacent channel. You usually have to allocate some dead channels for the area to prevent receivers from being overloaded. So in that case would it be fair to say that receiver was using channels it had no right to when set to the weaker signal? After all, the transmitter was there before the receiver was...
Note that other countries have managed to deal with this routine and common issue with respect to the introduction of 4 GHz 5G. There is something weird going on in the USA...
This! The altimeters with issues are not operating to their design specs. No one noticed until 5g apparently but imo it’s on the altimeters, and not 5g, if they aren’t properly rejecting out of band noise/energy.
Unfortunately these altimeters are part of a very large critical infrastructure, which can't be ignored. Just saying they shouldn't be working that way doesn't negate the fact that they are working that way. Part of engineering is taking the real world into account, even if the real world is inconvenient for you.
>The altimeters with issues are not operating to their design specs.
Then what is the required passband attenuation at 220 MHz away from the centre frequency as per the spec? What altimeters are not meeting this spec?
I find it weird that people are claiming that the altimeters are defective here. That would be a big deal if true.
Then what is the required passband attenuation at 220 MHz away from the centre frequency as per the spec? What altimeters are not meeting this spec?
I find it weird that people are claiming that the altimeters are defective here. That would be a big deal if true.
So your suggestion is we ground all flights for 6-12 months while they retrofit new altimeters so you can have your phone battery die faster?
Yes, that’s exactly what OP proposed. /s
Ignoring reality isn't helpful.
If we go this way we would have to defund highway patrols because it is waste of time (traffic rules already specify how to drive safely). You don't need IRS (because law says how to pay taxes).
Also try to understand those pilots did not manufacture the equipment they are flying. They bought equipment that was certified to be airworthy or are flying for somebody who owns the equipment that was certified to be airworthy.
If we go this way we would have to defund highway patrols because it is waste of time (traffic rules already specify how to drive safely). You don't need IRS (because law says how to pay taxes).
Also try to understand those pilots did not manufacture the equipment they are flying. They bought equipment that was certified to be airworthy or are flying for somebody who owns the equipment that was certified to be airworthy.
So the solution here is to go after the planes/AOC holders that have misbehaving receivers and to force them to upgrade to correctly working hardware, just like we do with cars. Even if your car is certified, it will still get pulled off the street if it misbehaves - see Dieselgate. And company drivers also don't buy the cars they drive - nobody cares.
We are in this situation because the FAA is ignoring reality for some 50 years now. They think just doing nothing means nothing bad can ever happen; well, reality just caught up with them.
If I inject a new feature into production and it destabilizes existing functionality, it’s the new features fault (and it gets rolled back). It doesn’t matter if I really think it’s the fault of the other component, or I would have designed it differently (especially now that I know the consequences!). Maybe we end up “fixing” the existing functionality and then proceeding with the new feature — but not until stable state is re-established.
This is like standard practice for shit that is of trivial importance to humanity in a newish engineering field. So I don’t for the life of me understand the logic of being more flippant when it comes to human lives in a more established engineering field.
This is like standard practice for shit that is of trivial importance to humanity in a newish engineering field. So I don’t for the life of me understand the logic of being more flippant when it comes to human lives in a more established engineering field.
I want the pilots who have my life and the lives of my friends and loves ones in their hands to be entitled to whatever they need to safely do their jobs.
Well their companies bought defective equipment, and now wants someone else to pay but not using a resource that the airplane companies are using for free.
I see 3 solutions: 1: shut down 5G. 2: Ground airplanes with defective equipment 3: Make the airplane companies pay for the spectrum that their defective equipment needs to operate.
Option 2 would satisfy flying safely and not put externalities on companies that had no fault in this. 3 also would but would not be very efficient.
I see 3 solutions: 1: shut down 5G. 2: Ground airplanes with defective equipment 3: Make the airplane companies pay for the spectrum that their defective equipment needs to operate.
Option 2 would satisfy flying safely and not put externalities on companies that had no fault in this. 3 also would but would not be very efficient.
> Well their companies bought defective equipment
No they didn't. The equipment worked just fine until people started broadcasting on a nearby frequency.
Like if I put a jammer outside your living room window and your WiFi stopped working, would that be because you bought 'defective equipment'? After all, your router doesn't have the latest 'anti-jamming' error correcting codes built in.
No they didn't. The equipment worked just fine until people started broadcasting on a nearby frequency.
Like if I put a jammer outside your living room window and your WiFi stopped working, would that be because you bought 'defective equipment'? After all, your router doesn't have the latest 'anti-jamming' error correcting codes built in.
The equipment is indeed defective. If your receiver is able to be overloaded by adjacent channel interference because you as the designed neglected to install a bandpass filter on such a critical piece of equipment, and it wasn't discovered until later when someone legally was granted a license to use adjacent spectrum, your equipment is WILDLY defective. Just because it took many many years to identify the failure doesn't give the manufacturers a pass.
A jammer is a malicious, unlicensed product specifically designed to prevent your Wifi from working.
A jammer is a malicious, unlicensed product specifically designed to prevent your Wifi from working.
Unless I misunderstand the altimeters did not live up to the required specifications when they were produced, but as the nearby spectrum was not in use nobody really cared about this.
It wasn't the equipment working fine that made it defective. It was the fact that they were using frequencies hundreds of MHz away from what they were allowed to use.
The planes were in spec at their time of production, and in working condition before the 5g rollout. Imagine carriers installing some new technology near highways which causes cars with a device installed before 1999 to occasionally crash. You can't just say "too bad, those owners should have upgraded by now".
Regardless of what the specifications say, you can't rollout new technology without taking the real world parameters into account, and these were well-known parameters before anything rolled out.
Regardless of what the specifications say, you can't rollout new technology without taking the real world parameters into account, and these were well-known parameters before anything rolled out.
Probably because less harm is done if you have lower speed for browsing than when a plane crashes or the air traffic is decimated. But I am just guessing.
The airplane pilots can't do shit about it, it's up to their parent company to pressure company (and pay $$$) that sold them planes to fix it.
From their perspective it worked for decades and now someone decide to jam it.
From engineering perspective, yes, they are defective and don't have enough filtering on the input to stay within its band
From their perspective it worked for decades and now someone decide to jam it.
From engineering perspective, yes, they are defective and don't have enough filtering on the input to stay within its band
From engineering perspective, the 5G equipment is not staying in its band, not radar altimeters. Remember that the regs for band usage are on transmit, not receive, and the physical reality makes radio altimeters especially hard to filter.
No the altimeters are sensitive to frequencies outside their band. So 5g transmitting inside its band causes the altimeter to malfunction.
Many receivers can be affected by strong signals outside of their band. The strange analog world has effects like desensitization and intermodulation, which can produce in-band signals or attenuate the ones you intended to hear. The degree to which a receiver is immune to these effects is part of the engineering of the receiver. They likely didn’t consider strong C-band transmissions with a high duty cycle in their design at the time.
Also in multiple threads on this before, people more versed in analog radio electronics described how problematic it is to filter.
I don't think you understand FCC rules about communications at all. You can't just freely snoop on someone's cell phone call because you are just receiving. There are all kinds of regulations around reception.
And I think you do not get the rules about frequency allocation, which don't care about separate rules related to snooping communications.
So regardless of 5G C Band is indeed the cause or not, why aren't they testing it in a controlled environment? Make some test flights in good viewing conditions near those locations with the reports, and have turned on, data downloading/uploading 5G cell phones onboard using different planes/series and see if there's any interference happening.
I know it's more complicated and costlier than that but since lives might potentially be in danger and since it's too late to change the 5G bands, it seems to be the only viable option.
If it it indeed causes, C band can simply be banned near runways and say, be allowed inside the airport in low power settings if it doesn't cause interference with outside planes.
I know it's more complicated and costlier than that but since lives might potentially be in danger and since it's too late to change the 5G bands, it seems to be the only viable option.
If it it indeed causes, C band can simply be banned near runways and say, be allowed inside the airport in low power settings if it doesn't cause interference with outside planes.
The issue has been known and adressed in France for a while (and to my knowledge, France has been pioneer in handling the topic seriously. e.g. see https://www.anfr.fr/liste-actualites/actualite/la-protection... ).
5G base stations have compliant out-of-band emissions so the issue is not "because of 5G" but rather "because radio-altimeters gather energy from adjacent bands" (something we call "blocking"). Not all radio-altimeters are the same, but for some of them there is very little filtering and the only thing that protected them from good old 4G was that the antenna behaves somewhat as a filter and 2.6 GHz was far enough from 4.2 GHz... It may sound silly for a safety-critical equipment, but we really have to think about the really long lifetime of those equipments and think with the context of the time when they were designed/deployed (e.g. if there is only space-to-earth transmission in adjacent bands, why would they put filters that would add insertion loss and cost ? In the 80's there was no 4G/5G in sight...). Probably the aeronautical authorities also failed to inform the relevant issue in due time within the spectrum regulation process, so this has not been known or studied properly at ITU/CEPT/etc in the context of those frequency bands close to 4.2 GHz. It also seems that the radio-altimeters vendors keep a lot of secrecy on the technical details of their equipments (a part of the internal culture which also comes from the dual civil/military use of those systems) so even people who represent civil aviation authorities or aircraft manufacturers such as boeing/airbus in spectrum regulation authorities do not always have full access to the relevant information.
Now the situation is what it is, and the short-term solution is to have some kind of 5G exclusion zones around airports, and of course operators are not happy with this because they paid huge prices for 5G licences and now they discover that they have new/additional constraints around airports... Long-term solution is also an issue, because it is not that simple to put filters on existing equipments (if they change the behavior, the whole computer need to be re-calibrated, and pilots trained, and the whole thing re-certified, which is also not as simple of doing it once and certifying all aircrafts from the same model but really must be done one-by-one in a custom way for every aircraft). I understood that new specs for radio-altimeters will soon be out so we can hope that the situation improves soon as the retrofit will be able to start (even though it will take years), but there is a possibility that even new radio-altimeters may still continue to be vulnerable to blocking in 4-4.2 GHz in order to maintain their required accuracy (I'm no expert in radars but I trust those people who told me). So the issue will be solved with regards to 5G in 3.4-3.8 GHz as deployed in Europe, but maybe not above 4 GHz (which is one reason why it may be better to restrict to low-power/verticals in the future uses in those bands).
Anyway, this is a complex topic as you see...
5G base stations have compliant out-of-band emissions so the issue is not "because of 5G" but rather "because radio-altimeters gather energy from adjacent bands" (something we call "blocking"). Not all radio-altimeters are the same, but for some of them there is very little filtering and the only thing that protected them from good old 4G was that the antenna behaves somewhat as a filter and 2.6 GHz was far enough from 4.2 GHz... It may sound silly for a safety-critical equipment, but we really have to think about the really long lifetime of those equipments and think with the context of the time when they were designed/deployed (e.g. if there is only space-to-earth transmission in adjacent bands, why would they put filters that would add insertion loss and cost ? In the 80's there was no 4G/5G in sight...). Probably the aeronautical authorities also failed to inform the relevant issue in due time within the spectrum regulation process, so this has not been known or studied properly at ITU/CEPT/etc in the context of those frequency bands close to 4.2 GHz. It also seems that the radio-altimeters vendors keep a lot of secrecy on the technical details of their equipments (a part of the internal culture which also comes from the dual civil/military use of those systems) so even people who represent civil aviation authorities or aircraft manufacturers such as boeing/airbus in spectrum regulation authorities do not always have full access to the relevant information.
Now the situation is what it is, and the short-term solution is to have some kind of 5G exclusion zones around airports, and of course operators are not happy with this because they paid huge prices for 5G licences and now they discover that they have new/additional constraints around airports... Long-term solution is also an issue, because it is not that simple to put filters on existing equipments (if they change the behavior, the whole computer need to be re-calibrated, and pilots trained, and the whole thing re-certified, which is also not as simple of doing it once and certifying all aircrafts from the same model but really must be done one-by-one in a custom way for every aircraft). I understood that new specs for radio-altimeters will soon be out so we can hope that the situation improves soon as the retrofit will be able to start (even though it will take years), but there is a possibility that even new radio-altimeters may still continue to be vulnerable to blocking in 4-4.2 GHz in order to maintain their required accuracy (I'm no expert in radars but I trust those people who told me). So the issue will be solved with regards to 5G in 3.4-3.8 GHz as deployed in Europe, but maybe not above 4 GHz (which is one reason why it may be better to restrict to low-power/verticals in the future uses in those bands).
Anyway, this is a complex topic as you see...
> “I’d sleep like a baby [on a plane] that flew over a 5G base station at full power output,” he told Spectrum. “Probably something happens that’s unusual and the pilots attribute it to 5G but maybe it’s not attributable to 5G. After everything in the news, they’re now submitting what they actually see, whereas before they perhaps weren't motivated to do that.”
This is just pure speculation.
This is just pure speculation.
[deleted]
My main takeaway from the article is that it is scary that aircraft safety is so dependent on a signal that is so easily generated and spoofed.
From the article it sounds like anyone can go to an airport and simply send some garbage signals towards an approaching aircraft to make it deploy air breaks and crash if the pilot is not quick to react.
When I think about it it seams like a common thing in aviation tech. ads-b has similar issues, it is completely unauthenticicated/unsigned there is 100% trust.
Anyone can pretend to be anyone else.
From the article it sounds like anyone can go to an airport and simply send some garbage signals towards an approaching aircraft to make it deploy air breaks and crash if the pilot is not quick to react.
When I think about it it seams like a common thing in aviation tech. ads-b has similar issues, it is completely unauthenticicated/unsigned there is 100% trust.
Anyone can pretend to be anyone else.
Could this also be why my dad's satellite TV reception with a C-Band LNB has been degrading over time (as his area slowly gets 5G coverage)?
Yes, very definitely. The new 4 GHz 5G transmitters are now adjacent to the existing downlink band and are causing interference to those users as well. Your dad might have to get an LNB with specific filtering or a separate filter and that might not work if the transmitter is close enough. Hobby dish owners have no protection here. They can't exclude 5G transmitters from their vicinity like a commercial dish operator.
Relevant discussion:
* https://www.intelsat.com/wp-content/uploads/2021/02/intelsat...
Relevant discussion:
* https://www.intelsat.com/wp-content/uploads/2021/02/intelsat...
Damn, ok thanks for the info!
LNBs can degrade over time - he may just need to replace it.
hmm... I actually didn't think of that, ok will check.
> anonymously share safety incidents and concerns
Why? It is not like there is serious privacy violation in telling that altimeter broke, and this makes the data much less reliable. Not saying the data is fake for sure, but I have came across enough haters of 5g, and I am pretty sure someone could post fake entries just to scare people.
Why? It is not like there is serious privacy violation in telling that altimeter broke, and this makes the data much less reliable. Not saying the data is fake for sure, but I have came across enough haters of 5g, and I am pretty sure someone could post fake entries just to scare people.
ASRS (https://asrs.arc.nasa.gov/) is how both private and commercial (including ATP) pilots can anonymously and non-punitively share safety or otherwise concerning events.
The goal is data collection to assess and prevent incidents. NASA's intake on the reports are not anonymous, but their public reports are. NASA functions as the filter between pilots and the FAA/NTSB.
The goal is data collection to assess and prevent incidents. NASA's intake on the reports are not anonymous, but their public reports are. NASA functions as the filter between pilots and the FAA/NTSB.
Because the airline industry isn't too keen on pilots reporting safety issues. Fear of retaliation would stifle reporting if anonymity could not be ensured. This has nothing to do with 5G.
The airline industry is very keen on pilots reporting safety incidents. Over the years it has moved more and more towards being a no-blame environment: as long as an incident is immediately reported and wasn't due to gross negligence, you will not be punished.
If pilots are not afraid to report incidents, they will report them more often. This in turn means that hidden issues are more easily discovered, which in turn could save lives.
If pilots are not afraid to report incidents, they will report them more often. This in turn means that hidden issues are more easily discovered, which in turn could save lives.
I wonder if Europe just lucked out there or if someone there actually had that in mind when setting the spectrum.
The European Union is surprisingly technocratic, which is why a lot of complaints from Americans about EU regulation seem archaic to us. (Ie the debate that always pops here in HN about the EU restricting innovation by forcing chargers - this all sounds silly to Europeans because we’ve never seen them make a bad decision and stick to it for decades after it’s outdated US style).
I'm not able to parse the bit about "the EU restricting innovation by forcing chargers". What kind of chargers are we talking about?
The EU requires a USB-C PD compatible charging port for smartphones and other small devices starting in 2024(?).
This is primarily directed at lightning.
This is primarily directed at lightning.
one thing I've noticed since 5g has been introduced in the UK is that 4g has gotten significantly slower and less prevalent. has anyone else noticed this?
Not at all - in fact what I have noticed is that 4G seems to be far more reliable than 5G (on a Galaxy Fold 3 here) even in strong signal areas.
In the US, carriers are allowed to brand an enhanced LTE service as "5Ge." That may account for there being fewer times when your phone shows "LTE" or "4G" as the connection type.
That's not unexpected after a while, as the telco switches prioritisation and bandwidth from 4G cells to 5G cells, as happened with 3G to 4G. But it's too early for it to be happening at a noticeable level and might mean your provider has underinvested in capacity.
Just a guess though.
Just a guess though.
Many phones (certainly iPhone 12 behaves this way) will show 4G LTE link as being "5G" when they are connected to eNodeB that is capable of 5G in NSA mode regardles of whether the link actually uses any 5G NR bearer channels or whether it is actually physically possible (interference, path loss, gNodeB antenna configuration...) to use NR channels.
Thus you can pretty well observe a lot of what really is 4G as 5G.
Thus you can pretty well observe a lot of what really is 4G as 5G.
The 5G band that was auctioned off is only one step next to the band used by radar altimeters - essentially a piece of equipment on aircraft that gives it its precise height above the ground.
Aircraft can and do have barometric (pressure corrected) and GPS altimeters as well (which are usually giving you your height above sea level - and knowing the height of the terrain you can work out your height above ground), all of which feed into the various systems allowing them to have an accurate height at any given point during the flight.
This is most needed when flying “precision 3D approaches”, usually in bad weather when visual contact with the ground may not be possible until the wheels actually touch the ground. Autopilot systems that land the aircraft fly these “approaches”, and thus rely greatly on their height, speed and distance.
These radar altimeters were mostly designed and certified back in the 80’s (or even earlier!) - and it’s a lot of work to have any equipment certified - especially today. Hardware + software back then was nowhere near as good as it is today, yet many of these altimeters still being produced today would be to the original spec from a few decades ago - which had a much wider tolerance or sensitivity to the frequencies, so when you have a frequency only a few steps away - a slightly older / worn equipment with perhaps not the best shielding will definitely pick up some surges from frequencies next to it.
Blame the FAA for their archaic and slow, near impossible process to get equipment certified. Blame the Aircraft / Equipment manufacturers for not updating their equipment with the times, but that’s on the FAA for making this process difficult- see 737 certification as an example, leading to the max accidents.
See https://en.m.wikipedia.org/wiki/5G#Aviation