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Comment by Aurornis | Hacker News Reader

> When you take this info and combine it with the ability of Wifi7 routers to "see" where people are in their house,

WiFi routers can’t tell you where people are in the house. The routers don’t even know their own location within the house.

All of those papers you see on the topic have extensive additional information being put into their models. The routers don’t magically know the layout of your house.

At most, a WiFi device could infer movement in a house if the RSSI of devices is fluctuating where it is normally stable.

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Couldn't someone standing outside figure out where interior routers are by triangulation, simply by walking around the house?

Kinda: ESPARGOS: ESP32-based WiFi sensing array

https://espargos.net/

Isn't that already enough for a heads up display? Direction relative to where I am point and shoot? I don't think the layout of the house matters that much since the person using the 'wifi' router strapped to their back/head can already see what's in front of them?

So combine it with a plan made from a social media posting.

Or a robotic vacuum. Or one of the other thousand houses with the same layout in the neighborhood

Or a Roomba... One of the first things they want to do is make a plan of the house.

But also, don't builders have to submit plans of homes to the local government when building them for approval?

Most robot vacuums (at least the ones that use LiDAR, which seems to be the majority) can only capture a very rudimentary plan of your house, that being a 2D image taken at an elevation of ~10cm or so. It will also be obstructed by any large objects, and there's no easy way of telling them apart from walls.

Your government probably knows your floor plan (though, I don't think they tend to be publicly accessible). Either way though, neither of these methods are anywhere near enough to do what was shown off in those Wi-Fi tracking demos. Here's hoping the tech doesn't get a lot better or has a series of unexpected breakthroughs.

Floor plan isn’t enough for a location model. These have to be learned in from accurately tagged data combined with measurements taken at the precise time of the tagged location data. A lot of tagged data.

You’re not going from a floor plan to a precise location model. Just think about how different the WiFi environment would be if someone put their router next to their steel computer case versus someone setting it on a nice MDF cabinet with no wires nearby. Completely different RF environment and pathing.

Not just social media postings but past real estate listings can probably provide floor plans.

And if you don't have those, a lot of buildings have common patterns. Its very much in the realm of possibility to train a model using exterior and interior information so that you could have AI generate a floor plan using only exterior data.

Combine that with a small drone that could fly around a building and take different wifi signal readings to triangulate access point positions.

Once you have all that don't you have everything you need to detect movement in the building based on signal disruptions?

Yes, seems like a bit of work but it absolutely seems like the type of effort some governments would put effort into.

>Combine that with a small drone that could fly around a building and take different wifi signal readings to triangulate access point positions.

That seems like all you'd need anyway, skip the rest of this. Small autonomous drones with simultaneous location and mapping capability will absolutely revolutionize warfare (and firefighting, but I digress) whenever they stop being sci-fi.

> Not just social media postings but past real estate listings can probably provide floor plans.

I regret even engaging with the floor plan debate.

It doesn’t matter if they have a floor plan. That’s not enough information to characterize the RF environment of a house and how it responds to people moving through it.

A floor plan won’t tell you the position of all the WiFi devices, obstructions, and how the environment responds to moving those around. It won’t even tell you where the router is with any precision or if it’s next to a big chunk of metal like a computer case that’s blocking half the house and causing reflections.

It’s a red herring.

The police has access to the planimetry of your home. Secondly, if they get close enough they can measure the distance between the agent and the router, and then deduce all the relative distances from the router to the people inside.

This is sci-fi fantasy mixed with paranoia.

The floor plan of every home is not on file, especially older homes.

Police aren’t accessing your floor plan and then accessing your router and combining these into a perfect model that maps people’s locations. Where in this supposed plan are the police deducing the location of your WiFi router in the house and constructing a model of all materials and objects in the house that impact the model?

This just isn’t how those research papers work. It’s not something the police are going to combine with a file from the planning office and magically have a map of you in your house like in a movie.

They could easily find it for most people. It is generally public record, in my county it's available online, unless the individual built the home themselves (mine isn't on file because I opted out of building codes and planning, but commercial home builders can't do that here).

But let's be real, police constantly barge in to the wrong address, looking for people that have been gone for years, accomplishing not much more than shooting a beloved dog on a hair-brained last second witch hunt. It's not that they can't do it, it's that they have the attention span and executive planning facilities of a burnt out coke addict 3 hours post their latest scratch off ticket winnings.

(fyi, hare-brained... like a hare)

Depends on how far you go back with the language. https://grammarphobia.com/blog/2013/10/harebrained-hairbrain...

A floor plan is not equivalent to a complete RF characterization of an environment. Ignore the floor plan comments because they don’t enable WiFi positioning.

Think through it: Does your floor plan contain info about the precise location of your WiFi devices and any obstructions between them? Even that isn’t enough to get a WiFi location model, but it’s not in there regardless.

Yet. Given the availability of the data online and that most new startups are defense or security oriented, it’s only a matter of time.

Yeah, your local friendly police officer isn't gonna do that.

They're gonna pay Anduril, Palantir, and a whole host of other business or consulting firms a ton of your money to do that.

The criticism that "it's technically too challenging for the police department therefore its sci-fi" is extremely silly given that the current article literally is about private companies that are building surveillance networks that they will then sell to the police.

Which makes the entire situation a lot worse.

It's a lot cheaper to just bust the door down, toss in a bunch of flash bangs and light up anyone who doesn't have their hands raised. Maybe they'll just send an armed robot in first if there's a specific threat involved.

Everything about our world today was the stuff of dystopian paranoia 20 years ago.

Police aren't doing anything, they're worthless.

Tech companies are doing stuff and giving police free for all access and use. Which is worse, because as stated, police are worthless. You think they consider the consequences or the rights of the people they use those tools on? Come on now.

This can be provided as a service, if it isn't already. Im sure something similar already exists.

Police won't even check the address before they raid a place, so I don't think so.

Yep. I used to be a building/remodeling contractor. If I accidentally showed up to the wrong address and demolished the wrong deck, I'd be responsible for making the property owner whole again.

If a cop serves a warrant and the wrong address and ends ups murdering a child, that cop will receive sympathy and paid time off.

Yeah, people have (attempted to) sue PDs and cities for even woefully negligent wrong address raids (different street to warrant and documentation), and the courts have happily told them "sucks to be you, they have no requirement to pay for any damage".

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