Your TV can see through walls (2025) | Hacker News Reader

Your TV can see through walls (2025)

maurycyz.com

259 pointsCuriositry128 comments

Wait for people to learn about that you can listen in virtually anywhere through fiber-optic cables, as sound waves are enough to redirect the light in the cable to a measurable degree by "bending" the cable itself. Special devices to filter these variances out and transform them back to audio signals are a thing. It's only per line though, as any repeating device will just output a new cleaned up signal again.

Oh well, there have always been ways to snoop on someone like that. Back in the day it was CRTs emitting measurable waves through the neighborhood, with some papers even going as far as restoring the displayed image through a wall. Nowadays it's fiber and WiFi, and those seem to be much easier to work with even. Plus everyone carries a device that is tracked by their mobile provider's cell network. shrug

You can also listen for audio simply by measuring any vibrating surface with a laser. Which goes all the way back to the late 40s, used by the USSR. |

Fun fact, it was invented by Leon Theremin. The inventor of the Theremin.

1940s? The LASER device was invented in 1960. The Soviet spies used an infrared light beam.

The point was light being used for audio, not specifically laser as a light source.

You seem to keep responding to multiple people defend your point, but he used 1320 MHz in the thing which is not light.

the words you use matter.

Speaking of, "light" has no frequency cutoff. Radio waves are not visible light, but they are light!

They are not light, they are electromagnetic radiation, which light is part of.

There's no clear distinction!

Electromagnetic radiation is light, and light is electromagnetic radiation.

Yup: https://news.mit.edu/2014/algorithm-recovers-speech-from-vib...

You are completely wrong.

Here's what Theremin invented: https://en.wikipedia.org/wiki/The_Thing_(listening_device)

Theremin did invent the Thing (a.k.a. the Great Seal bug) that worked as a passive RF cavity. However, he later invented a completely different device called the buran eavesdropping system:

> Apparently happy with ‘the thing’, Beria called on Theremin’s services again and he was enlisted for further eavesdropping operations. In 1947 or earlier, when Theremin probably served in the Kuchino sharashka outside Moscow, he was called upon to create another device for wireless surveillance, but this time it should operate fully remotely without any device planted at the target site. The project received the code name buran (snowstorm). To solve this difficult task, Theremin paid attention to the resonators already present in a building, such as windows. A conversation in a room may cause window panes to vibrate slightly, and Theremin devised a method to detect these vibrations from a distance, using an infrared beam directed at the window pane, and then to interpret them and convert them to discernible speech (Glinsky, 2005, p.261).

> The buran was able to detect speech from as far away as 500 metres, making detection very difficult. Interception would have to disrupt the infrared beam and jamming would require optical overpowering. Both were unlikely. However, it could be used only when weather permitted and was not effective in rain, fog or smog (Glinsky, 2005, p.261). Buran is often considered a predecessor of the laser microphone, although it employed an infrared beam rather than laser.

https://www.jstor.org/stable/10.2307/48828289

Yes, he invented the technique of monitoring audio through light. How was I wrong there?

The Thing uses a radio signal at 330 MHz (or perhaps a second or third harmonic). These radio waves have a wavelength of about a meter, which is about 6 orders of magnitude longer than an optical wavelength. It's a fundamentally different mechanism than laser Doppler vibrometry.

> These radio waves have a wavelength of about a meter, which is about 6 orders of magnitude longer than an optical wavelength.

Radio waves are light. By definition, they are optical wavelengths.

Radio waves and visible light are both electromagnetic waves, but the frequency/wavelength are different by several orders of magnitude.

Right, but "optical wavelengths" are not limited to the visible!

For example, the company I work for manufactures DUV optics for the semiconductor industry and IR optics for the defense industry.

Given these common-use definitions:

https://en.wikipedia.org/wiki/Optics "Optics usually describes the behaviour of visible, ultraviolet, and infrared light."

https://en.wikipedia.org/wiki/Radio_wave "Radio waves are a type of electromagnetic radiation with the lowest frequencies and the longest wavelengths in the electromagnetic spectrum, typically with frequencies below 300 GHz and wavelengths greater than 1 mm"

I see no problem with using the term 'optical wavelength' to distinguish between a wavelength of ~1 micrometer and 'radio waves' at ~1 meter.

The next sentence from the linked Optics article:

> The study of optics extends to other forms of electromagnetic radiation, including radio waves, microwaves, and X-rays.

I have no problem with this usage if the distinction helps understanding, but we seem to be discussing terms with potentially conflicting definitions without defining them: laser, light, radio, optics. All of these can reasonably apply to MHz radiation!

And the next sentence is "The term optics is also applied to technology for manipulating beams of elementary charged particles."

No one disputes that 'optics' can refer to more than visible light. But, in the context of a discussion about lasers and 1950's radio devices operating at VHF, we can still use terms like 'optical wavelength', 'radio wave', 'light', etc to distinguish the phenomena.

Language is a two-way street. Words are imprecise tools for people who want to communicate together, even in engineering and physics. Being pedantic without a deeper point to make isn't a useful contribution.

I'm trying to address a misconception I see happening in this very thread:

> Yes, he invented the technique of monitoring audio through light. How was I wrong there?

> These radio waves have a wavelength of about a meter, which is about 6 orders of magnitude longer than an optical wavelength.

> The point was light being used for audio, not specifically laser as a light source.

> You seem to keep responding to multiple people defend your point, but he used 1320 MHz in the thing which is not light.

These comments disagree on important definitions. I don't think it's pedantic to point this out.

The context is a plausible energy source for illuminating a passive modulating reflector (a window pane or a custom cavity resonator) in 1945 Moscow.

There are three approximate frequency bands being discussed. The bands are separated by a factor of about 1 million. The width of each band is a factor of 3-8.

Human voice audio - 500 Hz to 4 kHz (the modulating signal)

VHF-UHF radio - 330 MHz and 1320 MHz

"Light" - 300 to 800 THz

> "Light" - 300 to 800 THz

This restriction to the visible is what I'm pointing out. (Note that the first person to mention the word "visible" was you!)

ClikeX clearly included radio waves in their intent, and that is an accepted definition! It's the definition I use in practice as an optical engineer.

If you actually have any new information about the wavelengths Leon Theremin was using, please share it.

ClikeX originally claimed that the USSR had lasers in 1945 (untrue) and that Leon Theremin invented the detection of sound vibrations or audio reproduction of via light (also untrue).

The confusion here is between the two different eavesdropping systems developed by Theremin: The Buran eavesdropping system (which used likely-near infrared on windowpanes) and "The Thing" (which used VHF-UHF radio on a custom device).

Your repeated insistence on the unrelated point that "light" and "radio" are technically both electromagnetic waves isn't clarifying anything.

Mate, I'm really not trying to argue with you. I'm not suggesting anyone here is wrong!

> If you actually have any new information about the wavelengths Leon Theremin was using, please share it.

I'm quite confident it was an optical wavelength! ;)

> ClikeX originally claimed that the USSR had lasers in 1945 (untrue) and that Leon Theremin invented the detection of sound vibrations or audio reproduction of via light (also untrue).

> The confusion here is between the two different eavesdropping systems developed by Theremin: The Buran eavesdropping system (which used likely-near infrared on windowpanes) and "The Thing" (which used VHF-UHF radio on a custom device).

Great summary!

> Your repeated insistence on the unrelated point that "light" and "radio" are technically both electromagnetic waves isn't clarifying anything.

I hope this has helped clarify that, of the terms used here, only "radio" is clearly distinct, since "light" and "electromagnetic waves" are often used interchangeably.

The ancient Chinese invented WiFi. They used the light from signal fires to send messages between towers on the Great Wall. WiFi uses radio waves to send signals, which are also light. Therefore WiFi was invented 1800 years ago by the Chinese.

Not much more of an exaggeration than the often-repeated claim that WiFi was invented by a certain actress-inventor.

https://en.wikipedia.org/wiki/The_Thing_(listening_device) is a fun read for people who haven't seen it before

>The theremin is an electronic musical instrument controlled without physical contact by the performer.

Funnily enough, first time I've seen it mentioned was in Ghost in the Shell manga from 1990s, where Major's side business illegally offers military grade optronic touch/etc senses in artificial skin for cyborgs, using measurements of bending fiber optic loops

Just toss a doppler laser interferometer on a window, mirror, etc. At least with fiber-optics you need physical access. Single mode (I think that's most of FTTH) is pretty insensitive to vibration and hard to localize so you'd really have to install something.

In this context, is line of sight with the ability to emit and receive laser radiation at the target not ‘physical access’?

Not for an exterior window.

Ah, but of course. How could I forget about my trusty pocket doppler laser interferometer!

This is a "high school project funded with pocket money" level of DIY, with €25 of parts.

Yours is not built in to your watch? You should go and have words with Q.

You'll need that to intercept fibers as well, plus a pocket fusion splicer to boot!

Microwave beam-forming says what?

I didn’t hear it say that. I guess I’m not the target. :P

Included in the next version of Flipper. /s

I don’t get your point. Yes, there’s a lot of eavesdropping techniques available to actors with nation state capabilities (or with a lot of time, money, and expertise). This is another one of them. It’s good to be aware of things like this because it helps you better understand threat modeling for applications that require serious hardening.

There may also be unusual applications of this, like the traffic counting mentioned by another commenter.

(For anyone who needs hardening against things like this, you need a SCIF.)

> Back in the day it was CRTs emitting measurable waves through the neighborhood, with some papers even going as far as restoring the displayed image through a wall.

It's been some time since I've thought about Van Eck phreaking: https://en.wikipedia.org/wiki/Van_Eck_phreaking

So when AI takes over the world, it will have a convenient tap into every living space of every hoomin. Lovely.

Fiber optic interrogators are (for now) expensive and bulky, so I don't think commercial modems are capable of that (yet).

trackers are also now becoming near microscopic

they track BUTTERFLIES from Canada to Mexico by attaching tiny trackers with eyelash glue

* https://celltracktech.com/products/ctt-blumorpho

smaller than a tic-tac candy (about two match-heads)

* https://cellular-tracking-technologies.github.io/ctt_documen...

Several years back we actually made use of the principle mentioned in this post, to more systematically count traffic on the roads [1]. In our case we used LTE/4G radio, and we could even estimate the direction of travel, as well as the type of traffic (pedestrian, small vehicles, large vehicles). It was more accurate than Google Maps because it was independent of the moving phone, i.e. it was "sensing the obstacles in the environment".

[1] "Traffic Flow Estimation using LTE Radio Frequency Counters and Machine Learning", https://arxiv.org/abs/2101.09143

As anyone observed who had a TV with just basic analog terrestrial antennas, before cable and satellite dishes - it does make a difference to the signal, when and where you stand and countless pieces of physical comedy in TV shows incorporated that.

As soon as I've read your comment, I've thought about this Mr. Bean's sketch: https://www.youtube.com/watch?v=4S9-vDow2d0

And reflections on other buildings (which usually cannot be compensated for,) wind bending antennas, etc.

Ah, the old ‘stand in a funny pose so the family can watch the show’. Such a classic. :P

See these for a very low cost (<$10) method for observing WiFi and some LTE spectra:

https://news.ycombinator.com/item?id=49922674

https://espargos.net/espsdr/

Amazing book about similar topics: “Silence on the wire” by Michal Zalewski

https://www.amazon.de/Silence-Wire-Passive-Reconnaissance-In...

Anything in my price range?

https://annas-archive.gd/

what is your price range?

it's from 2005. you can almost certainly find it in libraries or used.

it's also from 2005 -- some of the basics are still valid but it's dated.

What is your price range? You could check your local library for borrowing it.

Our kitchen FM radio would reliably lose the signal of the local NPR affiliate whenever someone was halfway up the basement stairs. RF is weird!

I thought this article was going to be about putting a webcam on the other side of the wall and streaming through the TV, which somehow had never occurred to me and I want to try it now.

I threw away all TVs in my house after the proliferation of ads on the Home Screen. Sorry, the only value a TV has is displaying images and audio at large sizes. Not getting me to shop. So I decided to get rid of them all and now I use large monitors and projectors. Make TVs dumb again.

The article is about radio waves from TV broadcast towers, not the TV in your home.

well, it's about the radio receiver in the TV in your home

Not really, it’s about anyone with a receiver that’s physically near you using radio “shadows” to detect movement. The author just happened to do these particular measurements using TV signals; they explicitly mention that radio signals in other bands also work.

This makes no sense.

This problem is solved via two ways (or both at once):

- Pihole

- Unplug the TV from ethernet and disable wifi

All my TVs display no ads because they are jailed.

> Unplug the TV from ethernet and disable wifi

This likely requires opening the case and physically disabling (hence knowing what you are doing). Or the TV will find other devices to transmit the data. Not an easy measure for everyone.

a TV cannot "find" a way onto the internet without your wifi password (don't say insecure wireless networks)

Amazon Sidewalk is an example of an opt-out long-range cross-household device mesh/relay network using Bluetooth and LoRa to exfiltrate surveillance data.

They are consumers and have no idea

Sure, if you discount the glaring wide open loophole your argument is perfectly airtight.

I know this is written to sound scary, but it's been like this since the invention of the radio/telegraph (late 1800s?). You're getting blasted by rf almost continuously, unless you live in a bunker.

This is written to sound scary/capatalize on a relatively underdiscussed snooping mechanism.

But it isn't at all like straight UHF/VHF radio intereference spectra analysis or whatever we want to call it.

Wifi, Cell network bands, bluetooth and hard fiber lines are all far more exploitable than "regular" RF . A police squad car equipped with the RF package (which convienetly comes from defense contractors) can grid out your home and hotspot people, devices, etc. This is only possible due to exploits/abusing these standards and cooperation w/ device/tech vendors.

Is this a problem? Eh, not for me where I live. Is it illegal? I am not versed enough to know how procedural/ y the books this is. But it is odd that a passing police vehicle potentially has unmarshalled/warrentless seach running 24/7.

In order for that to work, they would have to stand on one side of your house, and scan from the other side. If they're already surrounding your house, they might as well just bust in.

Having two guys with gadgets is a much lower bar than getting a court to approve them busting into your house.

They can rely on existing infrastructure. I assume you have cell service and wi-fi at home?

"I know this sounds scary, but don't worry - all this spying won't give you cancer!"

Tangential. Of both LG [0] and Samsung [1] smart TV's it is known they spy on you any way they can. Does someone know if they do that too for models sold in Europe, which would likely be in violent breach of GDPR?

[0] https://www.youtube.com/watch?v=6IFVTcM28KA (Gamers Nexus findings)

[1] https://www.youtube.com/watch?v=VFx1DyAjxYc (LMGClips summary)

Now, about the wifi part, why isn't there an Home Assistant extension that detects already room presence magically exploiting all of this??

There is: https://community.home-assistant.io/t/espectre-wi-fi-motion-...

There is with Zigbee: https://github.com/orgs/home-assistant/discussions/960

But this relies on Hue. I would like something at HA level directly, aka a zero-effort solution if you already run a zigbee swarm either directly controlled by HA or via zigbee2mqtt

See also: Van Eck Phreaking https://en.wikipedia.org/wiki/Van_Eck_phreaking

As made popular in Cryptonomicon!

So, a bad actor can now know when I'm at my house or not, I'm sure that's fine and won't be problematic

Bad actors, and any WiFi capable hardware in your house. There's an official spec for it[1], and some routers already have the option built in. I remember seeing papers about this over 10 years ago, someone at MIT did it for a paper.

Philips Hue also has it built in to their newer lights, where they measure the Zigbee signals. They call it MotionAware[2]. Basically anything with an antenna and a bit of compute is able to do this now.

[1] IEEE 802.11bf-2025 [2] https://www.philips-hue.com/en-hk/support/article/motionawar...

Even philips hue documentation is now vibed

It's probably just AI translated. The original docs are Dutch.

There's an official spec for it[1], and some routers already have the option built in.

~~Comcast~~ Xfinity actually advertises it on the radio as a feature.

> So, a bad actor can now know when I'm at my house or not.

A bad actor who wants to act on that information can just wait near your house on a workday morning and watch you leave, likely not to return for the better part of the day. No techno-voodoo required.

Bad actors have been doing that for millennia using their eyes.

This makes it more remote and subtle, but it’s not a new threat.

Not just remote, automatic as well. IMO an entirely new class of threat over "my neighbor knows when I'm home."

If the government wants to know if you’re home, they’ll know. That’s been the case for as long as there have been governments and fixed residences.

What is new, I admit, is they could retroactively know if you’re home on a date before they became interested in you, if they’re surveilling and recording everyone.

Even having three security cameras around the perimeter of your house can allow quite precise location and activity detection inside the house via their audio steams.

Those mics can be quite sensitive.

I don't have security cameras in my house but that's actually interesting to see how things most people have in their house can (and does?) used to spy on them.

Phones and smart TVs, probably other appliances. My SO used to be surprised to receive ads about stuff we talked about minutes before. I finally looked at her phone, disabled a bunch of things in the stock Android settings, those timely ads went away. I didn't even have to install Blockada, uBO for FF (and uMatrix and other addons) like I do on my devices.

Can you elaborate on what did you disable?

I feel like by disabling ads in most devices, I'm also taking away the best source of information on what bad actors (here ad companies) managed to exfiltrate about me.

If there only was a way to sell ad space about myself and learn from it what others know.

Most companies don't allow you to turn off data collection easily. What they do allow is turning off the response to that data (displaying relevant ads).

I mailed her a summary for future reference. It's quite detailed but it was not in English and the phone was not in English too. So forgive me but I asked Claude to translate it and guess the right menu and option names for an English Android. It should be enough to give you the idea of what I did. It was a Samsung phone, not a S series.

Here it is:

---

Tapping <first name last name> at the top of Settings opens the Samsung account notice, and the Terms of Service show as not accepted. I'm leaving them unaccepted and not continuing.

1. Security and privacy

Controls and alerts: left Microphone access on, because permissions will be set individually per app.

More privacy settings:

Send diagnostic data

Set to Off

Samsung

Improve personalized ads based on data from this phone: you have to go to the Samsung account settings.

Receive news and special offers on this phone: same

Customization Service for your phone: same

Going to Accounts and backup > Samsung Cloud > Data backed up: there is no data being backed up to Samsung.

Going to Samsung Cloud shows that Bluetooth, Calendar, Contacts and Wi-Fi are synced.

Google

Google personalization service: set to Off

Permission manager:

Switched to Ask every time:

  - Chrome
  - Maps
  - Meet
  - Facebook
  - Google
  - Messages
  - Speech Recognition & Synthesis from Google
  - Samsung Keyboard
  - TikTok

Still set to "Allowed only while in use": Camera and WhatsApp

Activity controls

Web & App Activity: turned off, but I did not delete the history

Timeline (Location History): was already off since January 1, 2025

YouTube History: left on

Personalized ads:

  - My Ad Center is turned off
  - Partner ads settings, Visit My Ad Center, Ads you can control, Get started,
    Cancel

Everything is disabled, as expected after turning off the Google personalization service

2. Ads

Ads privacy

Ad topics: 0

App-suggested ads: 0

Ad measurement: - Allow ad measurement: set to Off - Reset measurement data: reset

Reset advertising ID: confirmed, reset

Delete advertising ID: deleted

Usage & diagnostics: disabled

3. Remote management

After I tapped it, it said "Installing applications" After a few minutes, at the second login, I got in and it showed me a Smart Tutor screen. I went to Apps, found it and uninstalled it. It would have allowed the phone to be managed remotely by customer support, I don't know which one.

Facebook

Settings & privacy

Settings, Apps and websites, turned off "Apps, websites and games"

Business integrations

Activity log, Apps and websites off Facebook, Posts from apps and websites: it was empty. Your apps: it was empty.

Yes. But depending who is doing the work they can just see what Bluetooth devices are around each hour of the day too... It sucks that everything we have seems to be usable against us

and if you go completely dark whoever is interested can just install a camera near your apartment and get that info anyway. you just can't hide in a city if you are not actively trying to hide, never could either even before tech, it was just more expensive.

Really? They can’t seem to pick up a conversation happening directly in front of them.

Or they could just knock on your door and see if you answer.

They already knew this from your cell phone not being in airplane mode.

If I ever try to hide (which is probably impossible at this time and age), I will probably just break my phone not like I can use it anyways every single act in it sends data to too many places to count.

I assume the problem is still tracing and association. So long as there is no direct link between you and the device, there is no saying if that is you or not. So grabbing a used phone via cash transaction from someone and only turning it on and using outside of your usual locations could be enough to have it being "anonymous". Then, using a vpn or other proxy that hides your network can make you very hard to find, so long as you don't associate with your real identity in any substantial form.

The danger with these technologies is not when they allow to precise track you once your general vicinity is known, that was always possible by putting some goons after you. General mass surveillance that is constantly tagged is the problem, flock, PRISM and the other stuffs.

There was a TV show in the Netherlands, called Hunted I believe. Contestants had to go on the run and avoid getting caught by the hunting team without doing anything illegal. Or staying to long in a single place, so no camping in the middle of a park (which would technically be illegal anyway).

Long story short, barely anyone got anywhere. Because simply doing an ATM transaction to get the cash already triggered the signal where they were. Not to mention the amount of government owned cameras. As well as being in proximity of anyone still online.

Complete anonymity is virtually impossible, depending on the country.

The problem with that show is it is all simulated. They have a camera crew following them round so they cant exactly hide properly.

The show is set up so that if the contestants do anything on a given list (like access ATMs, pay for something with a known card, walking past cctv cameras etc) then the camera crew would notify the hunters. Thats how they got that intel so that they wouldnt need to use actual methods.

I dont think you can use that show as an actual example of somebody on the run. Its so far away from reality and set up to be interesting to the viewer, its just not realistic at all.

My point is that there are a gazillion contact points in any modern environment where you lose anonymity. Not that they can track you in real time like that.

The amount of camera's in and around shopping areas is staggering. And the requirement to have a smartphone on hand is increasing every day, at least in the Netherlands.

If that list is set up right, it mimics what a rogue government has access to.

Hunted is a different case tho, there they know the person's identity and need to find there location (and direction).

In the parent case the supposed illegal activity is associated with a device (possibly the location) and they are trying to find the identity of the person associated.

A good reason to keep a moderate amount of cash hidden on hand. Not so much that losing it would ruin you, but enough that you wouldn’t need to visit an ATM if you actually needed to hide for some reason.

Yes, I always carry at least $1000 in case I have to suddenly go on the lamb from tech-savvy three-letter organizations.

And three passports for three different identities.

Well it’s also good for emergencies where you might need to evacuate.

You can be identified quite quickly by other factors if someone with access to data is looking for you. Some factors are writing style networking metadata (who do you contact) and search queries. Especially big data companies (facebook google) are tracking you even if not logged in. Some of these factors are very hard to change from one moment to another, and most people are unaware that this data is used.

The problem with mass surveillance is that even if you are aware you are actively transmitting and your data is still caught in the dragnet for example with camera doorbells and other surveillance apparatus like flock, or visiting a site with facebook ad trackers. You transmit either way by being, if you travel in public with phone or without a phone, both is an identifying datapoint.

there is always the risk of the isolated Faraday caged house

Can't they already do that by snooping on ARP traffic on your home LAN? Failing that, if they can get whatever shitty wifi chipset they're using to enter promiscuous mode, they can also sniff all STAs that are in the vicinity, and with some ML they can probably figure out which MAC belongs to your phone.

Had to pull out my calculator to digest the calculations, phew. I'm a math major that's been out of the game for a bit, I guess i'm getting rusty.

Thank you for more paranoia

Awareness of possibilities is not paranoia. One implies sickness. Healthism?

π RuView turns commodity WiFi signals into real-time spatial intelligence, vital sign monitoring, and presence detection — all without a single pixel of video.

https://github.com/ruvnet/RuView

Just so anyone who reads this knows: This is a well known SCAM repo. The install instructions are incomplete and when you manage to get it running you will realize the data it produces is just random except for pre-recorded simulated data. If you check youtube for it you will find hundreds of completely AI generated Videos with not one of them showing the actual thing working. And all while trying to sell you some hardware.

https://github.com/deletexiumu/wifi-densepose " SCAM ALERT: Technical audit reveals this project is a non-functional AI-generated facade with fake CSI data, no trained models, and suspected star inflation"

Slight aside, but I went to look at some of the open issues on that ruvnet repo to see if this is discussed. It's quite an eery feeling reading through them. Every "discussion" is just bots talking to bots.

So it's the modern version of "smoking banana peels to get high"? (Which was a well-known "fact" in my youth, supposedly injected by the FBI to reduce drug use.) (It doesn't.) (<-- personal investigation)

yeah, now I gotta unplug TV too

That won’t help, this is about TV station signals broadcast from outside your house

There's no TV here. There's an ATSC broadcast signal and an SDR with a waterfall display.

Thats nothing, my old tv could predict incoming phone calls.

When I was young I could tell when the neighbours turned on their tv by the UHF whine.

I’d rather have the Chinese lady with the nice ass sex my secrets out of me

IEEE ISAC, look it up

see also, presence detection of humans via wifi signals: https://arxiv.org/html/2308.06773v2

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