Comment by rich_sasha
5 years ago
I can't scan documents when my daughter is asleep. When she is awake, all is fine, but the minute she goes to sleep, and I'd like to use my free time to scan documents and suchlikes, forget it. I could still print documents on the same device though. Here's what I found:
The printer-scanner was connected to wi-fi. The wi-fi router was in my daughter's room, as that is where the cable socket was, tucked just behind a bench in her room. It was also near that bench that her baby monitor camera was standing. It wasn't wi-fi connected, but for whatever reason it interfered with the wi-fi signal. Same with the receiver, if I put it near my laptop, the wi-fi connection would die.
The monitor was off most of the time, and on precisely when my daughter was asleep.
As for why I could still print, just not scan: presumably that's something to do with the bandwidth, I'm guessing it took more wi-fi bandwidth to send a scanned image than to print a document (I never printed pictures on this printer).
Yeah, baby monitors are THE worst behaving radio devices. They would be second after malfunctioning neon sign transformers, but transformers are not intended as radio devices.
As for why scanner and not printer losing connection - probably printer has small buffer and scanner doesn't pause when that send buffer is full due to trying retransmissions, but stops completely. Printer probably can wait for more data.
And yet there are people out there who will still try and argue that Signs is not a brilliant film
Still... my thinking is, I'd rather a crappy baby monitor than a badly-secured device connected to wifi, and by extension, the whole world.
We do actually have a spare camera we sometimes take away, that works on Wi-Fi. I accidentally left it once at my parent's place, then travelled back home overseas. I got a notification of my baby crying desolately as I got off the plane. Turns out it was my family arguing something in the room where my daughter was staying, and the camera somehow switched itself back on. It was freaky!
The main reason 2.4GHz band is unlicensed (anyone can broadcast on it without e.g. a ham license) is because it's garbage. Baby monitors and microwave ovens are two of the most common offenders for dumping large amounts of noise into that band. If you can move the printer to a 5GHz band, that could help a lot.
And in the near future, wifi 6E will add a ton of spectrum, allowing devices to just avoid noisy channels. But to use that you'll have to upgrade the printer or add a wifi 6E bridge.
Had a Customer who complained that the Wi-Fi in one of their conference rooms was "always" unreliable. I checked it multiple times and didn't find any problems-- low SNR, strong signal, low airtime utilization.
Eventually I learned out that "always" meant a particular recurring lunchtime meeting, scheduled right when a steady stream of workers were going into the break room across the hall and heating food in a microwave oven.
I had a Panasonic 2.4Ghz jamming device. Could take out channels 1-11 all at the same time. It wasn't supposed to be a jamming device, it was supposed to be a cordless phone. Setup wifi for a customer, and it worked fine when I was on site. Later the customer complained it was completely unusable, in what they thought was a random fashion.
Turned out whenever they used the cordless it pretty much made so much noise on the 2.4G frequence wifi wouldn't work. Phone itself worked fine. Had them get new phones and the problem went away.
I recall one of my colleagues at British telecom who told a story that when debugging random noise on the line.
It turned out to be the subscribers (a little old lady) budgie swinging on its perch was causing the problem.
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You really want to think about moving the Wi-fi out of the baby's room. Get a GQ-390 meter and you will see the torrent of dangerous radiation flooding her room, above recommended levels.
I was able to get my Internet provider to relocate the device to my basement.
I just exposed myself to radiation from the largest fusion reactor in the solar system! Should I panic?
....errr....
Wait.
I have just been slipped a note that the first sentence I wrote means "I just went for a walk in sunshine."
I have a fun story about the sun.
I used to work for an IPTV provider (who also happens to make a search engine). We received TV feeds from TV stations via satellite; we had an antenna farm, received their signals there, compressed/encoded the signal, and then sent them to customers over the network. Because we only had one antenna farm, we would have TV outages throughout the year -- sometimes the satellite happens to be directly in front of the sun, and the sun is a huge RF emitter that would overwhelm our receivers. (I asked if we can just move the satellites, but was told that we didn't have the delta-V budget. We eventually built another antenna farm. Another question I asked is why can't the TV stations just send us video files over the network. Apparently it simply isn't done; they have used satellites for decades, so why switch?)
Better stay inside, the outdoors are bathed in a torrent of EM radiation from around sunrise to sunset, every day.
In fact, the other people in your home are bathing you in infrared radiation when you're near them.
I bet you believe in 5G conspiracies too
Really? I don't know much about that... is it that the norms are unsafely high for these devices, or is it that most kit doesn't quite meet them?
Could you point me to any articles etc. on this?
Thanks in advance!
My comment is an unresearched, not even cursorially google-searched, from-memory assertion, so take with 5 buckets of salt please, and if I'm wrong I'd like to correct my ignorance, so someone please correct me :)
My understanding is that Wi-Fi, cellular (no matter the 12345G) and radio signals are all harmless in 99.99999% circumstances as they are non-ionizing radiation. They are no more harmful to you than light photons.
In fact, Wi-Fi signals might be safer than light. Since you don't have eyes sensitive to the EM wavelength of Wi-Fi, you can't shine a 'wifi light' too brightly next to you.
Damaging radiation as we think of it is most often in the form of ionizing radiation such as too much sunlight, microwaves that excite water molecules, or high amounts of alpha / beta / gamma particles that can mess with DNA etc. and thus cause cancer as DNA damage accumulates.
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