Posted by tsujamin 3 days ago
I remember the PM working on this feature showing us their research on how iPhones rendered bars across different versions.
They had different spectrum ranges, one for each of maybe the last 3 iPhone versions at the time. And overlayed were lines that indicated the "breakpoints" where iPhones would show more bars.
And you could clearly see that on every release, iPhones were shifting the all the breakpoints more and more into the left, rendering more bars with less signal strength.
We tried to implement something that matched the most recent iPhone version.
So, game-theoretic evil?
And while we're at it: Just surface the fact that connectivity sucks to applications (maybe even at the socket layer, by just closing them if there's not been any forward progress for a certain time), rather than showing me loading screens that'll never go anywhere for minutes.
This would give apps that do have some offline caching the chance of falling back to that (looking at a certain green music streaming service here).
There are some comments here: https://developer.apple.com/documentation/systemconfiguratio...
One thing explaining this might be that advancements in antenna design, RF component selection including the actual circuit board and especially (digital) signal processing allow a baseband to get an useful signal out of signal strengths that would have been just noise for older technology.
In ham radio in particular, the progress is amazing. You can do FT8 worldwide (!) communication on less than 5 watts of power, that's absolutely insane.
The signal strength measurement is actually standardised: https://en.wikipedia.org/wiki/Mobile_phone_signal#ASU
Unfortunately I don't think it's that simple. I've seen one phone simultaneously show significantly different numbers of bars for two SIMs installed in it for the same exact network and operator. After a while they become similar... then differ again... etc.
I have no clue how to explain it yet, but what I do know is that it literally makes no sense with a naive model of how these work, whether you try to explain it as reception or deception.
After selecting, each SIM slot is subject to inter freq / inter RAT reselection / handover.
Both are controlled by messages received from the tower (e.g. on 4GLTE, for reselection, System Information messages), though there is an additional constraint: what's supported by/enabled in the phone.
Perhaps one SIM slot was in the connected state and the other was in the idle state at one point. So the reselection logic applied for one and the handover logic applied for the other. There is for example a problem called ping pong handover. Once a phone is switched to a different frequency or RAT, the tower may have the phone be sort of stuck in the new frequency, until the conditions of the previous RAT or frequency improve substantially, in order to prevent the phone being like a ping pong ball between the two. This frees resources that would otherwise be spent on repeated handover-related messages.
Each frequency has its own signal strength (free space path loss, transmit power, one frequency might be on one tower and another might be on another, etc).
You're making huge and incorrect assumptions here, no? This also happens when your phone is entirely idle... and it randomly changes if you sit still for some time...
So your phone is basically always doing something, and frequently sending and receiving data when you assume it's doing nothing. By design, radios hop around between channels as conditions change. Another device somewhere outside your house kicked off a big transfer and your device hopper channels to avoid interference. Random atmospheric conditions introduced new noise, or another channel cleared up. This is standard, normal behavior for WiFi, Bluetooth, cellular, and essentially every other type of modern digital radio.
What you're seeing is normal and expected behavior. Modern radios and operating systems are vastly more complex than you're assuming.
I guess the bars aren’t realtime but updates every x seconds? I summed no malice.
Android is quiet lazy searching for towers.
This suggests that the issue is not related to Android.
No idea why, especially since I'm the one who installs ad blockers and such. Her phone is essentially stock.
Some generations, different Apple models have pretty different radios. Is there a difference in bands or ?
That might be the worst app I’ve used on my iPhone in a year. Better off vibe coding an app to give you signal strength.
I don't need to install an app on my Android phone to see my network signal strength. It's kinda hidden though.
Settings->About Phone->Click the sim slot you want to see info for
As near as I can tell, the smallest subcarrier 5G can use is 15kHz, the thermal noise floor for a 15kHz channel at room temp (300K) would be -132 dBm.
My guess is whatever chip doing the measurement simply couldn't measure that low accurately, or it reports "nothing detected" as -140 dBm.
"Tests carried out by research group PolicyTracker, and shared with BBC's Morning Live, found that nearly 40% of the time a phone displays the 5G symbol, it is actually using a 4G connection"
Interestingly that company built a bridge of sorts allowing providers to get more life out of their older hard and software, converting e.g. 5G signals to 4G and 4G to 3G (where a signal is for example a phone phoning home telling the provider they used a megabyte of data, or looking up the IP address when calling a phone number)
Also where 2/3/4G network signals were all their own protocols (RADIUS and DIAMETER), 5G is just HTTP. And where for the 3G/4G stuff they had to write their own code to handle the protocols, for the 5G stuff they just used the cURL library. That is, cURL powers 5G networks.
Human brains: wow, what a bunch of suckers. Damn.
By the way, is it legal to be deceptive in this way?
I do.
I'm from Germany, land of perpetual EDGEing. Highest total GDP in the EU but can't build a mobile network for the life of it.
Then again we somehow forgot how to run trains and build cars without cheating, so I guess it fits.
Want to see a single bar? Come visit, our carriers aren't on the list with that inflate flag enabled. I guess they didn't get the same memo as the car manufacturers ;D
> Then again we somehow forgot how to run trains
The mobile networks don't have enough dB and the trains have too much DB?
I still can't get over the justification for abandoning the €9/month universal ticket experiment (and replacing it with a €49/month offering which has since been bumped to €58/month and will soon be raised to €63/month) officially being in part that "rail will be worse when more people use it" (the other mostly being "not enough people used it to demonstrate its value" and "people used the ticket for trips they otherwise wouldn't have been able to afford to make").
We should just nationalize it all properly and make it free at point of service. Let tourists use it for free too, obviously. Infrastructure exists so the economy can happen, its ROI is a functioning industry and society so stop trying to pretend we can reasonably measure its success in profit.
https://en.wikipedia.org/wiki/Afsluitdijk
Yet, when we visit family in Germany, five minutes after crossing the border we are in a cellular dead zone.
Perhaps the route being so busy is the cause of the connectivity issues, but it's still baffling to me how bad it is, given that the amount of mobile devices trying to connect must be very predictable.
I'm pretty sure the in-train internet also relies on mobile networks, so that's unreliable too. Plus any bandwidth is taken up by people scrolling through tiktok.
The short version is that the chancellor we had in the 1990s didn't like how the public broadcasting channels were talking about his failures and wanted to push the development of private broadcasters (who being beholden to financial interests rather than objective news coverage mostly spoke favorably of him) by prioritizing cable television over fiber. A surprising number of things came downstream from that pivotal decision, e.g. the completely braindead way we sold frequency bands (which resulted in some literally remaining unused because there were initially no requirements to actually do anything with them).
GDP per capita (or GDP per square metre) would be a more useful indication here. Otherwise, you could throw a bunch of poor countries together--just for purposes of statistics, and expect a better mobile network?
However Germany is still very high in both GDP per capita and GDP per land area. Roughly on par with the UK, and far higher than France which has a much better mobile network
Well, it would be the best metric, if your country was homogeneously populated.
If everyone lives in one big city and there's literally no one in the rest of the country, then I expect mobile reception (and every other service) to be pretty good for everyone, because they all stay in the big city.
> However Germany is still very high in both GDP per capita and GDP per land area. Roughly on par with the UK, and far higher than France which has a much better mobile network
Yes, France, Germany and UK are all equal enough in these measures (well within an order of magnitude) that the much bigger difference in mobile networks is most likely due to some other factors.
Sometimes the reception is good but the data rate is poor because of too few towers per person, or because the cellphone companies connections to the wider internet are saturated.
GDP per square metre only really works for countries with uniform population density. For example, by European standards, Spain is huge, and basically entirely empty outside of a handful of cities...
Even with the EU single market, mobile phone operations almost always follow country borders. You'll get a different set of providers in Germany than you'll get one km away on the other side of the Rhine in France. Even though some of them may have the same name or the same ultimate owner or both, and even though you can roam on the other side of the border, you'll have a contract with a different entity, and different people will build and maintain the networking equipment.
Conversely, in the US, the major carriers all have nationwide coverage.
Coverage is decent on Telstra, but if you're out of town reception is rarely any good, presumably because there's little to no incentive to improve it when there's no on around to need it.
The few farmers I know have a rough idea of the on-the-ground cell coverage. They say things like "this side of the hill/town" usually. I've seen them deliberately walk to the other side of a silo to make a call.
I assume that the coverage maps are assumed cell-tower-coverage-if-shit-is-not-in-the-way. No surprise radios are common.
Tangent but this is a pretty interesting topic. I've heard people speculate that local politics deliberately prevents such infrastructure, waiting for some kind of kickbacks to make it worth their while. Others suggest that it happens because federal telecom subsidies aimed at improving rural connectivity don't apply, as a kind of retaliation for tribal sovereignty. Way off-grid, ok, maybe it's simply not worth it to corporate telecom, but whatever the cause coverage even in fairly populated areas around Kayenta/Monument Valley is also quite bad in a way that would be infrequent in comparable communities in say, nowhere Appalachia.
Many a suburban parent of smart-phone addicted children would romanticize the whole thing and actually be kind of jealous of a situation like that. Years back and on the other side of the world, tourists were very scandalized about more roads and towers around Annapurna in Nepal.. but of course the locals usually do not actually like to be cut off from the world.
More telecom is probably good despite the evils, but fuck commercial billboards in particular. Those are still creeping closer to the Grand Canyons and Yosemites, and they suck whether it's for multinationals like McDonalds, or for locally owned gas stations or hotels that put cash into tribal communities. Ban them all like Hawaii, and everyone will be astonished to learn that the world keeps turning..
I work with cellular BDA-DAS[1] gear sometimes, and I don't recall the last time I looked at the signal strength display on my phone. It has probably been years.
For me: It either works, or it doesn't work. It is either fast-enough, or impossibly-slow. It's very binary, and the bar graph at the top never told me a damned thing about what I should expect.
[1]: Bi-Directional Amplifier, Distributed Antenna System. In theory, such constructs can make indoor cellular coverage quite good inside of buildings that previously had none. In reality it can be... complicated. And while the bar graph doesn't mean anything, I still need ways to see what's happening as I spend hours, days, or [sometimes!] weeks surveying and troubleshoot and stuff. The phone can report things like RSRP, RSRQ, and some other tasty bits instead of just a useless graph -- and from there, I can sometimes make a hand-waving guess as to what I may reasonably expect for performance.
But that stuff is normally pretty well hidden from view.
A few months ago, I was in a remote area at anchor on a sailboat, about 6.5 miles from the nearest highway through the swamp, with only a few farms and a handful of houses within that radius. With my phone up in the cockpit of the boat and tethered over WiFi to my laptop, I was able to download a movie. As the boat swung on anchor, the download was occasionally interrupted, but when data was flowing it was consistently 5-10 MB/s over a claimed 5G link; the movie downloaded in much less time than its runtime. I assume I wasn't competing with much other traffic on that tower, wherever it was. So my experience was even more binary than yours.
The phone's signal indicator did seem to accurately indicate when it had no usable signal at all, but beyond that I'm not sure it was providing any useful information. And I'm not sure if it could have told me anything of use other than "connected" or "not connected". The very marginal connection was still faster than I had any right to expect for those conditions.
The net is telling me this is because of the aisle after aisle of tall metal shelving and the building itself also has a lot of metal in the construction.
It is quite annoying when you are trying to use the Home Depot app to look up something.
They finally added WiFi a year ago or so.
I hated having to walk near the doors to send a “was it this” question to the wife.
It must actually be tricky to space out towers that sparsely without creating any obvious coverage gaps, but if anyone is up to the task, it's certainly Vodafone (let's not talk about the actual service quality, though).
Wifi-calling to the rescue :)
Phone calls are hit-and miss without WiFi calling switched on.
Looking at satellite view it is clear that the local municipal water tower is between a huge cell tower near the highway and my house. All carriers seem to lease that same tower only in my area.
It wasn’t like this when I moved in but I guess the carriers consolidated on that big tower near the highway about two years ago.
Radio shadows are a thing I guess.
But one bar is death for Internet - though HN will often load; anything heavier won’t.
I don't know if I want my name on an open source project attached to a commit whose only purpose is to lie?
That's not something I was expecting to hear
But then of course if you can push a customer one way or the other it will be to the higher margin product.
Like what Apple does with stopwatch.
https://lukashermann.dev/writing/why-the-iphone-timer-displa...
The countdown in question doesn't display fractions of a second so it would immediately switch from "5 seconds left" to "4 seconds left" which just doesn't feel right. Adding 0.5s solved the issue.
If you're counting up, round down. If you're counting down, round up. A human expects the count to finish at precisely the moment we get to the last number in the sequence (zero, for counting down). Do a count in your head to see what I mean.
Apple chose a compromise by rounding to nearest, for it to "feel good", but you lose the ability to exactly predict when the timer ends as a human. Typical Apple.
This signal strength is straight up lying about the actual signal strength
(Probably a way to do it on Android, too)
A CSR showed me this while debugging network connectivity issues with my phone.