The WiFi only works when it's raining (2024)
predr.ag146 points by epicalex 10 hours ago
146 points by epicalex 10 hours ago
I've collected a list of fun stories of this form and post them when this comes up:
- Car allergic to vanilla ice cream: https://www.cs.cmu.edu/~wkw/humour/carproblems.txt
- Can't log in when standing up: https://www.reddit.com/r/talesfromtechsupport/comments/3v52p...
- OpenOffice won't print on Tuesdays: https://bugs.launchpad.net/ubuntu/+source/cupsys/+bug/255161...
> Can't log in when standing up
This reminds me of a recent issue I had. I had just gotten a new laptop from IT. While picking it up from them, I had generated myself a password, put it in my password manager on my phone, and then entered it twice to set it on the laptop. Everything worked great. But when I got back to my desk, the password didn't work! I tried a bunch of times, watched myself hit each key to eliminate typos, etc.
I went back to IT and they asked me to demonstrate. But this time it worked! I walked back to my desk, thoroughly embarrassed. But a couple hours later I had to log in again and once again could not.
After thinking about it for awhile, I realized that I was typing at IT while standing over a sitting-height desk. Sure enough, typing in that position fixed my issue. I carefully watched what I was doing this time - something about the exact layout of the keyboard and the weird angle I was typing at ensured that I was making a particular typo I typed in that position - just a single letter switched to another, every time. Sure enough, making that one substitution to my intended password got me in.
Here's another for your collection.
- Putting the car in reverse sets off the neighbor's home security system. https://www.reddit.com/r/cars/comments/7k12fs/neighbors_hous...
Did this get solved? I think I read all the comments from OP but saw no confirmation as to what happened.
Ok I swear I had a printer that would do some kind of internal cleaning noise thing every time I plugged something else in to a 120v outlet anywhere in the same apartment. I never really tried to figure it out.
The vanilla story is insane!
It's not real, but it's still a fine story.
How do you know?
It's an urban legend that's floated around in various forms: in some it's an ice cream parlor rather than a store and they pack the vanilla faster, in some it's only the vanilla that gets hand-packed so it takes longer, it's pistachio that takes longer and triggers the problem, or butter pecan.
Snopes covered this one and they cite to an urban legends book from 1989: "Curses, Broiled Again" by Jan Harold Brunvand. Brunvand prints the "vanilla takes longer" version and reports also having a "pistachio takes longer" version printed in a magazine in 1978, which itself referred to another magazine as its source. In the book's version it's a Texas car dealer who's looking into the problem. The same author's later book from 1999 covers the story again and includes versions dating back further, plus a 1992 version which is this one where it's Pontiac and the problem is the vanilla being in a separate case at the front of the store.
In the Pontiac version you can go and pick at various implausible details stacked up together, that Pontiac's president cares enough to send an engineer out, that the engineer is there when the car won't start on the first night but still just comes back many more times rather than looking at the car or presumably noticing that it starts a couple minutes later, that this guy is buying a new container of ice cream every night and never stocking up, that he never takes any other trip where it's a short stop...
Maybe there's some kernel of a true story in there, but if so it's probably a pretty small kernel. Anyway it doesn't matter much: it's just a fun story that teaches a little lesson so people like to share it around.
My only unsolved networking mystery was that my computer would experience high packet loss when a Roku in the other room was streaming Netflix.
My PC and the roku device were both wired to two different ports on a router (iirc an Edgerouter X running openwrt at the time). This didn't repro when the roku streamed other services (hulu/youtube tested), only netflix. This also didn't repro if the roku was connected over wireless (connecting to an AP wired to a different port). Just opening netflix also didn't repro, the roku had to be actively streaming a netflix video.
I never ended up solving it, I just worked around it by making the roku connect over wireless.
It did take me forever to figure out the problem though. For a long time I'd be in one room getting frustrated with my computer while someone was innocently watching netflix in the other room.
QoS?
Does sound like a QoS thing, but I would think QoS still applies over WiFi so I'm not sure
Oh, wow. This sort of happened in my life!
My grandmother's house is adjacent my parents' w/ 200 ft. between and line of sight. Back in 2013, when my grandmother moved into the then-new house, I setup a point-to-point wifi bridge between them to share my parents' Internet connection and give me easy remote support access to grandma.
Summer of 2023 visiting relatives complained the Internet service in grandma's house was slow and unreliable. There were repeated suggestions made by helpful relatives for purchasing a new WiFi router for her house, getting independent Internet service, etc.
Grandma was happy with it, and the relatives went home, so I put off looking at it. When I did finally look at it, months later (when I went over for Thanksgiving) everything seemed fine.
When the relatives came to visit in summer 2024 they complained again. I looked at it immediately and found massive packet loss on both ends.
The ornamental trees planted along the driveway between the houses were the culprit. With the leaves off (say, at Thanksgiving time) it was fine. When the relatives came to visit in the summer the trees were in full leaf and acting as very good attenuators.
The trees were newly planted when grandma moved in. I didn't even think about them getting bigger and fuller when I set up the link. They filled out in the 10 years intervening, though. (Chalk it up to me still being relatively young and not thinking about installations on 10+ year timescales when I put it up.)
Fortunately there's a room in her house with line of sight to my parents' house unobscured by trees. It meant putting the radio outside a bedroom window instead of the attic (where I'd originally stashed it), but it solved the problem and ended complaints from relatives.
For GHz signals water is a pretty good dampening material, I can tell on some links whether it is foggy!
Your microwave uses 2.4 GHz specifically because it's particularly well absorbed by water :)
A friend told me once that his mouse stops working when someone is using the microwave. His room was on the backside of the kitchen.
When I took a look at it, it turned out that his (proprietary) wireless USB adapter for the mouse was very close to the band of the noise of the microwave. The microwave was also not properly grounded and shared a circuit breaker with his room, as apparently the kitchen was formerly larger and then split into two rooms by the landlord.
That was quite funny seeing that problem happen in action, he was always joking about a ghost in the machine, and I was joking about him being radiated by his microwave.
The cool part is years later in University one of my commilitones told me that his mouse stops working when the fridge turns on. The first thing that I checked was whether or not there's noise on the power circuit, et voila, easily fixed.
Noise on powerlines is annoying, very frequently present and sometimes dangerous.
Long ago there was this case of a factory that pressed desks out of steel sheets. Their main press (an absolute monster) had taken someone's arm off and they couldn't find the cause. It turned out that near the roof there was an air conditioning unit that that had a flaky relay in it that drew a gigantic spark on disconnecting, enough to upset the latch that controlled the safety interlock on the press, causing the press to move by itself.
It took quite a while to find it.
> A friend told me once that his mouse stops working when someone is using the microwave. His room was on the backside of the kitchen.
I had to disable a 2.4ghz access point a couple years ago because a bathroom had a passive IR detector for the light switch that would never let the light shutoff. Because detecting IR is a pretty weak signal, I guess these switches amplify it. The issue is the circuit also acts as a weak antenna for 2.4ghz and thinks its seeing IR when it's actually just amplifying and seeing the 2.4ghz beacon signal.
RF gets weird. Something I've thought about over the years is how my FM radios at my old house would sometimes pick up aviation radio which should be AM well above a tuned FM frequency. Apparently this is due to the common design being a superheterodyne receiver which comes with a few quirks (such as causing some small interference itself when it's receiving).
If you strum an electric guitar and let the hertz of the string fall through the range of AM radio the amp will briefly pickup AM radio stations. Not that you can decipher anything but you recognize voices as it travels past the station.
This happened in my life too!
I had a Customer complaining about bad WiFi in a conference room. Every time I checked it I had good performance. Eventually I attended the meeting most of the of the complaints related to just to observe.
What I observed was workers from cubes near the conference room microwaving food for their lunch in the break room right across from the conference room.
That's a common myth. There is no special water resonance at 2.4GHz, it's just a frequency allocated for general use. Early microwave ovens didn't use 2.4GHz
My first thought was atmospheric effects, i.e. along the lines of "The radio only works at night": https://en.wikipedia.org/wiki/Clear-channel_station
Also worth reading: https://en.wikipedia.org/wiki/Sporadic_E_propagation
I must say, the AI-generated "stock image" doesn't add that much to the article and could be done without, especially when its alt-text contains the prompt.
I once moved into a new apartment, built a new PC, but noticed that every 30 or so minutes while gaming my monitor would turn off. It was just frequent enough to make gaming intolerable. One day I was plugging something in and moved my DisplayPort cable slightly and my monitor turned off again. Turns out it was too close to the antennas for the WiFi card I had; it was inducing a current in the DisplayPort cable and the monitor’s firmware didn’t know what to do so it just crashed! I moved the cable slightly further away and it never happened again.
Similarly, if you have one of those office chairs with a pneumatic shock, dropping down hard on the chair may induce an electromagnetic or ESD pulse that shocks the monitor.
There’s a video on YouTube about this somewhere and we were able to confirm their findings.
Oh my god, so THAT'S WHY sometimes when I get up from the chair in my office, the screen flashes black for a brief moment?!
Yup! I don't know what the exact mechanism is, but google "monitor flashes when I sit on my chair" and you'll find tons of hits.
I have a Samsung Odyssey G9 monitor and it’s so sensitive to EMFs, it’ll blink off for a moment when I take my jumper off.
On two separate instances 4 years apart in Liberia, the VSAT unit and Asus WiFi router were overheating at peak usage or peak heat times. This must be happening more than is generally realized.
Easiest solution: permanently point a good case-fan-sized USB fan on to the unit, using its own USB port.
Long time ago I had a 10km 2.4ghz wifi link with directional antennas, it worked very well but the throughtput improved with rain.
Directional antenas are far from directional, they pick noise from everywhere.
In my opinion rain reduces that noise, and if the point to point has more than enough signal margin to keep operating at full speed, it ends up improving the link.
Something like horse blinders.
Man having dealt with so many wireless issues I already had a shortlist when I read fixed wireless was involved.
Either the radios were misaligned and the rain was reflecting it back towards a stable link just enough to improve throughput.
Or
The rain took a bad link all the way down, failing over to a different link.
Or
The rain/wind was moving an obstruction.
I have about a million of these stories sadly.
"The internet goes down on tuesdays"
Crane.
"The internet goes out in the morning"
Temperature inversion.
“The car won’t start after I buy ice cream”
The old classic, I think it turned out that in hot weather the fuel line vapour locked a few minutes after turning off, and the ice cream was at the back of the store, and took just long enough to walk there and back to trigger the issue.
Huh, my initial expectation was wrong! I figured (even until close to the end of the article) that the problem was a dramatic increase in the amount of wi-fi or other 2.4GHz traffic in the area leading to interference, some of which was blocked by rain thus allowing more stable local connections.
This reminds me of the printer that never prints on Tuesdays.
Just a guess. But after the first couple of paragraphs I realized it was a tree. Kept reading. Yup. Tree.
The rain would move branches out of the way.
This is why experience helps. Good life and professional experience helps to short circuit many problems.
I expected this
The fix was easy: Prune the branches. than
>The fix was easy: upgrade our hardware. We replaced our old 802.11g devices with new 802.11n ones, which took advantage of new magic math and physics to make signals more resistant to interference.
Easier, and probably even cheaper to upgrade a pair of wifi transceivers than negotiating with the neighbor to cut his tree.
Mainly because error correction is not free, you pay for extra bits and retries.
We had a Time Warner tech blame moisture in the air impacting the (sheathed) cable for an outage.
I was fully prepared for the wet walls of the building to act as a reflector.
I'm surprised WiFi can't pass on reliably through branches. Must have been a nightmare back then.
I would guess that the interior of leaves are quite conductive and that this accounts for most of the attenuation and scattering.
Update: this comment on the original posting of this article suggests so: https://news.ycombinator.com/item?id=39896699
Kind of tangentially related to weird ways tech works: a few weeks ago I finally disassembled my original DMG-01 Game Boy to fix it. There was decades of battery acid corrosion that took a ton of cleaning and resoldering and reflowing the screen connections.
After hours and hours of iterations I could get it to work perfectly, just once, for each cartridge. I would clean it a bit more, try a game, things would work great. I’d try another game and it the copyright logo would fail. So I’d clean it up a bit more. Swab the port and try it again. It worked! Then another game… nope.
I eventually realized that the isopropanol was making a weak connection work fine, and then I guess it just kept working once power was flowing.
No matter what I tried I couldn’t get it to stay fixed, so I keep a handful of cotton swabs and a small dispenser of isopropanol in the carrying case. I’ll swab a cartridge before inserting it and it works every time.
So now I have a Game Boy that requires alcohol to work.
(2024)
Discussion then: https://news.ycombinator.com/item?id=39896371
Related:
We can’t send mail farther than 500 miles (2002)
Just read this in the comments (https://news.ycombinator.com/item?id=39899534):
> I wonder how much polarization affects things; I was once told that terrestrial FM Radio is transmitted with vertical polarization to reduce interference from tall objects between you and the transmitter.
> Terrestrial TV (some of which used bands that overlap FM radio) uses horizontal polarization.
This is only true in the US (and probably areas influenced by US standards). In Europe, FM radio transmissions (and digital television nowadays) tend to be mixed-polarization (circular polarization), except if there are known interference (usually border areas) that would preclude mixed-polarization.
Analog television meanwhile significantly differs depending on your area, which required you to either test which tower and polarity is the best (note that all broadcasts are transmitted at a single tower, unlike in the US), or just... request a map with that data.