Any reason this wouldn't work with cell towers?
this post was submitted on 24 May 2026
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I imagine revolution decreases with range
I think the main advantage with the wifi-based approaches is that they are usually used in a relatively static/calm indoor environment with a stable channel response and your motions are disturbing that, compared to a quickly changing outdoor environment (e.g. a city) where it would be much harder to distinguish individuals. Also, you are typically closer to the access points, making the power/SNR higher. Regarding mobile communication though, the trend is towards higher frequencies and smaller cell sizes which also give greater spatial resolution (and higher power) and some funky near-field effects can be used to get beam forming on crack: https://arxiv.org/abs/2407.10147 So perhaps it could work even better, wouldn't be surprised
That's cool and all but if true, why use an animated photo instead of a real life example?
I'm not sure what you think an "example" would look like. It's not taking a photo of you, it's measuring what's distinctive about the way you personally mess up radio signals and how it differs from how other people mess them up. Internally it's just a ton of numbers.
Pretty sure this is old news? It's basically sonar, which The Dark Knight predicted in the film.
Edit: a word
Right? Im pretty sure this is a few years stale and already incorporated in some isps routers
https://www.xfinity.com/hub/smart-home/wifi-motion
https://www.originwirelessai.com/isps-can-do-more-with-wifi-sensing/
https://www.technologyreview.com/2024/02/27/1088154/wifi-sensing-tracking-movements/
There is a project I can't find now which uses an esp32 to create a presence detection system that integrates with home assistant and it uses wifi.
I know of ESPresense, but that only tracks your phone, not your body..
found the one i was talking about:
That's super cool! Thanks for sharing!
Product idea: clothing with jaged edges and radio absorbing plates.
My understanding is that this catches disruptions between devices and router. I don’t think this would work. I would say you should instead sell a “bracelet” with “ancient Himalayan Salt” embedded into the silicone to absorb and cancel the tracking. It would probably sell a ton! Obviously wouldn’t work but $!
Stealth Bomber Jacket.
Don’t give Musk the idea of the CyberShirt.
Necessary accessory called cyberBra for that real car hood look
Very interesting concept. I was curious about how in the hell this could be done. This article explains the general method.
When an inert object like a person moves around between the router and stationary connected devices like computers and printers, it interferes with the signal. The pattern of interference plus math can be used to plot the movement of the object - and even measure subtle changes like hand gestures. Home security software from companies like Xfinity can already use this tech to send you an alert when something is moving around in your house, without needing additional hardware. Imagine an informercial where a guy holds up a handful of "clumsy motion sensors" with wires sticking out of them, and "confusing instructions". Not if you just let your router do it!
As far as being a new and sinister means of surveillance, evil companies could already theoretically tap into anybody's motion sensors or security cams. The difference with WiFi tracking is that you wouldn't necessarily know it's there.
That's using CSI though. The article said the researches specifically did not utilize CSI.
But regarding CSI: I evaluated that as a small part of my Master's thesis and it worked pretty OK for motion detection but not for classifying other activities, at least not on a SISO link. For more complex stuff you would need both a MIMO access point (router) and device (e.g. phone). Also, you need to constantly transmit messages to get up-to-date CSI, which is not great for power consumption as well as cluttering the communication channel. There are some other constraints, especially regarding noise. E.g. I managed to completely destroy the CSI spectrogram by turning on a microwave oven. There is 802.11bf in development, which is supposed to standardize this, because currently using CSI is pretty much a "hack", as it is not intended for sensing. Once this is widely adopted, I would start being worried, but not right now.
This is from my thesis:
That is extremely cool, thank you.
When an inert object like a person
Say waaaa?
inert meaning not a wifi device.
How do they identify a particular person though? I get you could see people as present or not or moving around the room, but it's insane that they would be able to tell facial features etc.
The wavelength of a 5 Ghz wifi signal (the highest frequency in common use for wifi) is a little under 6 cm. So as a crude measure, it's not going to resolve spatial features much smaller than that with much reliability.
I think as a person moves about the waves would get a clearer picture.
A paper from around a decade ago talked about using WiFi to identify key strokes so with large data models we have today I would assume they could get pretty good fidelity on a person. Maybe not enough for “beyond a reasonable doubt” but probably enough where your WiFi company is selling your data on what you do at home
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It would be great if there were some open source tool kits for this. If the technology is going to exist it should be in the hands of the people.
Yeah, if this shit hast to exist, at least let me use it for presence detection in Home Assistant without having to buy separate sensors or something!
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Opensource tech to do the same thing has been in the hands of the people for a long time. This is just a different way of doing it without motion sensors.
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From what I've read this is built into the required wifi router for Xfinity. I discovered this when I signed up for Xfinity fiber, had the fiber installed and setup and then cancelled it the same day, because of this and not being able to buy and run my own hardware, and needing to install an app on my phone to manage the router, and apparently not being able to choose my DNS. They required that I rent their hardware for an additional $15/mo. Oh well, at least fiber is in the house now, if anyone wants it in the future. I sure won't be paying them to spy on me.
Fuck Comcast, still.
Damn. Put a faraday cage around the router and plug in your own router to a LAN port.
Wrap it in aluminum foil.
Whilst this sounds a lot like a foil hat joke, that's literally the easiest way to wrap something in a conductive material cage (i.e. a faraday cage).
If you don't want it to look ridiculous, put it inside a box whose inside has been lined with aluminum foil.
Mind you, personally I too would just cancel that shit, but the option is there to carry on using it whilst blocking its radio emissions.
app to manage router
This shit was a pain in the ass and now learning about this makes me feel even more pissed off as a customer
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"This technology turns every router into a potential means for surveillance," warns Julian Todt from KASTEL. "If you regularly pass by a café that operates a WiFi network, you could be identified there without noticing it and be recognized later -- for example by public authorities or companies."
Later...
Inexpensive or older routers either don’t store history at all or keep it for a short time.
Newer models can store more information for more extended periods.
https://www.thetechwire.com/how-long-does-a-router-store-history/
That's connection history. CSI motion detection software storing information it collects would be entirely independent of that. How much it saves and for how long would depend on the size of the router's memory.
We used to recommend people to run the newest stuff possible, but we came to a point that maybe it's better for us to keep with older tech for a good while
Or go to more civilized countries for vacation to get not backdoored hardware.
From what I've just read, the tech doesn't seem ready to identify people yet. It can supposedly detect hand gestures, but facial recognition I seriously doubt. But that's probably just a matter of improving the tech. See this article for more info.
From OPs linked article...
In tests involving 197 participants, the researchers said the system identified individuals with nearly 100% accuracy. The recognition remained effective regardless of viewing angle or how the participants walked.
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Have fun watching me be balls deep in my partner, fed boys. Be jelly cause you can't fuck like me.
I'm already envious 🙂↕️
I'm sure you fuck good or will one day if you haven't already.
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