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MIT Develops Accurate System For Tracking People, Objects Via WiFi (softpedia.com)
An anonymous reader writes: MIT's Computer Science and Artificial Intelligence Laboratory has created a new system called Chronos that can accurately detect the position of electronic devices in a room -- as well as the users who are carrying them -- within tens of centimeters using Wi-Fi signals only. "Chronos works without the aid of any secondary sensors, only using a technology called time-of-flight calculation, which measures the time it takes data to travel from the WiFi access point to the user's device," according to an article on Softpedia, citing a paper (PDF) that the researchers presented at a USENIX symposium in March. "MIT researchers say that by multiplying the time-in-flight value they receive from each user with the speed of light, they were able to detect each user's distance to the central Wi-Fi access point."
Just what we need, more tools for the government and advertisers to exploit.
Good thing I don't have a WiFi chip implanted into my skull. And I'm not glued to my goddamned phone, so MIT will need to step up its game if it wants to track ME.
slashdot: A failed experiment.
Without bothering to RTFM, does this mean that if they have two (or more) WAPs and the device was connected to each that they could get an accurate location? As it is, it seems that by using in-flight times, they can only determine distance from the WAP which isn't so much a location but a locus of them.
MIT invents signal localization?
active or passive?
With free wifi in airports, there's going to be massive privacy breaches.
All of the major WiFi equipment vendors (Cisco, Aruba, etc.) have offered this for some time -- though they don't claim anywhere near the MIT Lab's level of accuracy. For instance, Aruba calls their offering "ALE" or Aruba Location Engine. It sits as a separate virtual appliance and communicates to the central WiFi controller (AirWave in their parlance) or to the individual APs if they are operating in autonomous mode. It gets signal strength indications for each WiFi and bluetooth antenna in range of the APs (note: *not* just those devices that are Associated with the WiFi networks served by said APs) and feeds that into ALE. From there, you can map out the devices. Both Cisco and Aruba's products have very extensive APIs to access this info. Maybe they can enhance their offerings with MIT's new technology and get the location resolution improved a bit. For now, in the wild, it's often difficult to get a station (i.e. device) location down to better than a range of 3-10 meters.
Don't think this actually does localisation, just ToF-type distance. So it can tell how far you are from the access point, but not direction (unless they are doing something funky with the multiple antenna). In the main this just seems to be using multiple wavelengths to sharpen up and remove ambiguity from measurements (eg you can tell the phase angle, but need multiple such measurements to know absolute phase difference and thus precise range.
I don't want those republicans tracking me through airports. Is there anything we can do to fight this?
Garbage in. Garbage out.
This. With a push of a button they can track us.
I walk slowly. I don't want those republicans to know that.
Republicans are predators. You don't want them to know you are slow or weak.
This, and I wish MIT would stop helping the Republicans.
We all have enough to think about without having to worry about them tracking us.
And those republicans progress at an impossible rate. They know where they're going.
They attack us constantly. Attack us constantly.
(pushes button on phone)
(disables wifi)
there. now i'm invisible.
And predators attack the weak so you are screwed.
They peck away at us until something gives. Just look at all of the Hillary investigations. They have nothing despute over forty years of attacks.
The FBI hasn't even contacted her about emailgate, but those Republicans still claim there is an investigation.
They claim 147 FBI agents are investigating her, but no one in the media has found a single person that will backup that claim.
If there was an investigation someone would know about it.
This is starting to piss me off. I want those Republicans off my planet.
This. There is no evidence of an investigation. We need to concentrate our attacks on that fact.
We need to sterilize their kind.
Any reasonable civilization would.
They will never leave this planet as long as there are people to exploit.
What if they're testing us like we're testing them?
This. Never let a republican know you have a health problem. Our entire system is setup to abandon you.
Privacy is our last best hope for peace.
Equality was our last best hope for peace. That hope has died.
Once those pukianz engage, there is no hope. No hope.
And peace. Anyone dedicated to peace is an enemy of the Republicans.
I recall seeing the timing between stations on a wireless network being a common tactic to secure a network. If a station did not reply within a window defined by the time it would take for light to travel plus the time it would take for a secured device on the network to compute a reply then the packet was discarded. I'm sure that there are other methods to respond to such a packet beyond merely discarding it.
They seemed to make a big deal out of being able to do this with a single access point. Reading further I notice that they use other Wi-Fi devices on the network to compute a location which means that with only a single device on the network the ability to determine the location of that single device is diminished. To assure the location of a device they'd still need multiple access points and/or multiple client devices.
I assume that they take advantage of the MIMO capability of Wi-Fi devices that did not exist only a few years ago. This again is much like having multiple Wi-Fi access points, just treat each input and output antenna as a separate device and compute the location that way.
Perhaps I'm missing something important here but I'm not impressed.
I am armed because I am free. I am free because I am armed.
And sooner or later everyone is a victim of those republicans.
This, because war is so profitable.
But so many of them breed. Smart people aren't having children so humanity is getting stupid.
Swell
Unless Hillary is elected. She has a history of standing up to their kind.
Everything around a republican is altered.
The power of one mind used to be able to drive progress, but now with mass censorship and surveillance, that can no longer be true.
Republicans know everything about everything, but clearly know nothing about nothing.
They are an STD on humanity.
An article about this wifi-location technology was already posted here on /. on 4/1 under the title "MIT demos wi-fi that;s so high tech, it doesn't need a password." C'mon, guys.
https://mobile.slashdot.org/story/16/04/01/1417203/mit-demos-wi-fi-thats-so-high-tech-it-doesnt-need-a-password"
They already sleep better than us since they have better quality mattresses and sheets. It isn't fair.
Even sadder is that those Democrats are already using it to Track The People.
Yet sadder is that Democratic voters give ever more power to the government to implement this kind of technology.
Obama's record on civil liberties is piss-poor.
They are a political party. Shouldn't they be out politicizing something instead of ruining our lives?
We are broke. There's no way we can fight against their kind.
The only reason they get to call this an invention is because they're MIT... Phase detection/time of flight using multiple frequencies is nothing new; main limitation is the shitty clock most things have. Combined with the fact that you need fairly good signal chain components to do it properly. This system will still fuck up I'd guess when large metal objects come in play.
Now that would be a nice title for a PHD thesis: "Distance Estimation From Fart Noises: Signal to Noise Distribution and Error Patterns in Fart Noise Autocorrelation". Or something.
Why do you think there is free wifi in airport?
Is there any better place to spy high profile foreigners' devices than in airports?
You heard it here first:
April 4 2016, Cambridge: MIT students put their skills to the test to determine the distances between a multi-antenna WiFi access point and the remote devices using the Pythagorean Theorem.
So it can detect my casio watch can it?
Misleading article.
Actually, the airport is the worst place for wifi tracking. Lots of people leave their phone in airplane mode till they get to the hotel. And the government already track foreigners through customs & passport control anyway – no need for wifi there!
From the paper cited, direction is calculated assuming 2 antennas on the access point and 2 antennas on the client ... and then doing an optimization to find the most likely location. When it is correct, you have good accuracy. So the most interesting part is the calculation of time of flight as that is tricky over small distances given how fast light travels.
If they wanted to make it directional without all the caveats, simply beamform the wifi from the access point, and have it scan in bearing, the way radar of sonar does.
"Consensus" in science is _always_ a political construct.
In order to do 10 cm ranging (or "time of flight," as in this paper), you need (with a reasonable SNR, say 10), to have a total bandwidth of order 300 MHz. The 802.15.4a UWB standard provides better than 10 cm ranging, but with a bandwidth of 500 MHz, considerably wider than the bandwidth of a 802.11 (WiFi) channels. especially for 802.11b and its successors at S band (2.4 GHz), which are no more than 40 MHz.
This new Chronos system reproduces some of the technical capabilities of 802.15.4 using, not wider channel bandwidths, but a wider _spanned_ bandwidth, as in Very Long Baseline Interferometery:
To do that and get good ranging from it is a impressive technical feat, as you have to maintain phase coherency across these channels (i.e., you have to know the relative delays imposed by switching between channels, and you need to calibrate these to 0.1 nanoseconds or better).
This may make 802.11 WiFi competitive with 802.15.4 (both UWB and Zigbee); both are communications protocols, but 802.15.4 had, until now, much better ranging performance, which was needed if you want to locate, say, machinery in a factory. Given that everyone understands WiFI and tends to have it installed already, this could really give 802.15.4 vendors problems,
Isn't WiFi all about the speed of sound?
At least I saw a presentation at the IEEE 2015 International Radar Conference presenting using existing WIFI as the base signal for a passive radar. In their test setup they could easily track persons around in a room.
Sorry, I can't find the reference now.
No more random walk needed for Roomba?
The Xirrus Wi-Fi equipment has this capability built in. With the directional radio's the location has accuracy has always been this good. I don't see why MIT copying features already available to the public in existing technology is news. It is fine that some collegian wrote software to do the same thing as an existing product. But as someone else pointed out, all enterprise level Wi-Fi products have a version of this already.
Even sadder, the likely Democratic replacement is even further right than Obama on the issue. As an independent voter, I'd like to suggest to Democrats: you can't bring Trump any further down, your job is to try to show everybody that Hilary is at least slightly less of a terrible choice. You haven't yet and she certainly isn't making it easy.
We did this as a joke about 6 years ago at work using Fritz USB WiFi and Bluetooth Dongles. Nothing New here.
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