Wireless Positioning

An anonymous reader writes "This Intel-written whitepaper introduces a way to determine location with the aid of freely accessible, nearby radio sources, such as fixed Bluetooth devices, 802.11 access points, and GSM cell towers. Basically, the device reads the IDs of these local 'radio beacons' (each of which has a unique or semi-unique ID), looks up their positions in a locally-cached database, and performs a computation akin to triangulation. Intel created Place Lab in an effort to satisfy the emerging requirement for location-awareness within mobile devices such as smartphones, PDAs, and laptops, or even moving vehicles. According to the whitepaper, over four million of the required radio beacons have already been mapped."

Comments

Done before?

[Create an Account]

Wasn't this done before, or at least proposed before, by a private group? If I remember correctly we all laughed at the futility of trying to depend on WiFi and 802.11 access points to determin location. Are all of these hotspots less mobile now?

Re:Done before?

[mrseigen]

This appears to be done using GSM cell phone towers among other large, static objects.

One hopes those don't move the same way that wireless routers can (i.e. in a car)

Re:Done before?

[Zen]

Yeah, the GSM towers may not move, but if you RTFA, it mentions 2.2 million beacons, made up mostly by 802.11 AP's. However, take the example of only using immobile devices. What about catastrophe, and simple upgrades that are not in precisely the same location (ie, the opposite side of the same farmer's field). I did rtfa, and it didn't seem clear what the system would do in the case that a known mapped beacon changed location. In a largely populated city it would probably throw out the erroneous data because it does not match what is expected. But what does it do in a less dense area that only recieves a few beacons? In that scenario, I don't see how it could know that the data is erroneous, so I would assume it gives incorrect location information. It's still better than nothing, and it's great that people are trying to solve the problem. But from what I just read about this, I don't think it's ready for commercial use yet.

Re:Done before?

[rpresser]

Why can't the beacon devices themselves use this method to locate themselves relative to each other? Add a protocol for exchanging this information, and whatever devices are in the neighborhood could quickly reach a consensus as to their relative positions. And if one or more of them are GPS-enabled, voila, we have automagical mapping.

This idea was used in at least one Vernor Vinge story, "Fast Times at Fairmont High". The protagonists dropped wireless routers as "breadcrumbs" and after about four were down, they could accurately identify their position (relative to the routers).

Re:Done before?

[rpresser]

Dammit, should have used preview. Forgot to close the link. Anyway, the story appeared in 2001 and won the 2002 Hugo.

Re:Done before?

[theSpaceCow]

I've only skimmed the article, but something very similar was done by some of my friends in the University of Alabama's Computer-Based Honors Program two years ago. Main difference being that they only used 802.11 hotspots and not GSM towers. They published their results in the college's research journals, but since I can't even find the papers via Google, we can safely say they didn't get the word out enough for me to get uppity.

Roll Tide anyway, though.

Re:Done before?

[meadandale]

I worked on similar technology for my masters thesis. It was well known that triangulation resulted in significant locational errors (in the neighborhood of a dozen meters) which is all but useless in buildings when you are trying to find the closest printer or someone's office. The triangulation algorithms generally use a radio propagation model which isn't very accurate and is highly dependant on the physical construction of the building. Our work was based on research done by Microsoft

It turns out that the hardest part to adopting something like this was the work involved in creating the empirical signal maps for every single place that you wanted to use the service but the service itself could be very accurate.

Re:Done before?

[Anonymous Coward]

Because obviously you would need to equip every single of them with the necessary technology as opposed to simply entering their positions into a map.

Voila, another post where the author simply wanted cheap karma for spouting pseudo insightful gibberish.

Re:Done before?

[drewzhrodague]

Well, of course! I work on WiFiMaps.com, and we've been talking about doing this for years. It's the only natural outcome of wardriving data, if you think about it. There are few people developing location-based applications at this time, but there are a bunch of them. Some of the stupider people are trying to make a buck out of it, but this is just another feature of this Ubiquitous Computing that some of us are working on.

We've decided to GPL our data, so anyone can develop Google Mashups, or their own applications. In the meantime, we'll continue to collect data, homogenize it, and push it out for everyone to play with. Reminds me that we should mention this to the Placelab folks again.

WiFiMaps.com

Re:Done before?

[The employee can cho]

The private company is Skyhook Wireless

They hit the front page in June.
http://hardware.slashdot.org/article.pl?sid=05/06/ 21/2322250&from=rss

Re:Done before?

[Zen]

Interesting. I hadn't heard of that before. I wouldn't know how to set that up myself, but if it could be gotten working, then it would be a really nice GPS alternative. Most likely much, much cheaper, too.

Re:Done before?

[Bill Privatus]

IBM in Asia did some interesting research in 2004 - indoors, using WiFi...

Wireless LAN-based indoor positioning technology

Re:Done before?

[instarx]

I;m showing my age, but nothing is new if seems. I remember an old TV show (The FBI) where Efram Zimbalist, Jr. identified the home city of an abandoned car by pushing the buttons on the radio and noting the frequencies of each radio station. They then correlated all the radio stations in the country to find the one place all five frequencies were being used.

Re:Done before?

[rpresser]

Voila, another anonymous coward typing even though he knows hardly anyone will see his post at 0. Such courage, calling me an idiot while hiding behind mama slashdot's skirts.

I don't give a shit about (slashdot) karma, and I never have. I post because I believe that what I have to say is interesting or funny or whatever.

In order to get the positions so that they can be "entered into a map" you have to either use a GPS or do careful measuring or both. My proposal was a way that the devices could determine their own positions. Picture an army platoon dumping a few dozen boxes haphazardly around the battlefield, with cameras; wait a few minutes, and the devices figure out where they are; now you have a perimeter surveillance system.

Oh well. It's useless to try to argue with someone who isn't there.

Sorry, don't understand

[Unski]

[i]This Intel-written whitepaper introduces an determine their locations with the aid of freely accessible, nearby radio sources, such as fixed Bluetooth devices, 802.11 access points, and GSM cell towers. [/i] Whose locations? Who is 'their'? I cannot comprehend sentence as missing words.

Re:Sorry, don't understand

[Anonymous Coward]

All your access points are belong to us.

Re:Sorry, don't understand

[Frankie70]

This Intel-written whitepaper introduces an determine their locations with the aid of freely accessible, nearby radio sources, such as fixed Bluetooth devices, 802.11 access points, and GSM cell towers. [/i] Whose locations?


The Intel written whitepaper's location.
Whitepapers tend to get lost, like remote controls or keys.
This whitepaper solves the problem of how to find itself.

This is the Quine of whitepapers.

Re:Sorry, don't understand

[xTantrum]

Thats all fine and dandy to map your position when your out in the city or near cell towers and the like, what i really want to do is to be comfortable enough to take my cell out with me into the boonies and be assured that should anything go wrong i'll be able to triangulate my where abouts and send it to the local rescue service who are looking for me. Who really needs to know where they are when they still in the city, there are plenty of existing technoligies that already do that.

Re:Sorry, don't understand

[Unski]

echo "echo \"oh I see..interesting technology, those self-replicating white-papers..err brain hurts\";"

Re:Sorry, don't understand

[EnglishTim]

The point is not that *people* want to know where they are in cities, it's that their *devices* do.

For instance, you could tell your PDA to remind you to pick up something the next time that you are near a certain shop, or remind you to do something half an hour after you get home (giving you time to sit down with a nice cup of tea first...).

Re:Sorry, don't understand

[xTantrum]

But really who is gonna be sitting down with a nice cup of tea? they'll just find something else they just remembered they have to do to keep them running around with their heads cut off. I'm a techie and love some of the technologies that are out today, but sometimes...sometimes, i long for the old days. when seemingly life was simpler.

Why not GPS

[P3NIS_CLEAVER]

Why wouldn't people just want to use GPS? Is 'GPS on a chip' technologically feasable?

Re:Why not GPS

[thc69]

Because this is a neato satellite-free system. Also, because (maybe) it can be done entirely in software on existing hardware. From TFA:

Despite these efforts, building and deploying location-aware applications that are usable by a wide variety of people in everyday situations is arguably no easier now than it was ten years ago. First and foremost, current location systems do not work where people spend most of their time; coverage in current systems is either constrained to outdoor environments or limited to a particular building or campus with installed sensing infrastructure. Applications like location-aware instant messaging fall flat if they only work for a fraction of users or only during a fraction of a user's day.

Second, existing location technologies have a high cost of entry to both users and application developers. Many location systems require expensive infrastructure, time-consuming calibration, or special tags, beacons, and sensors. The privacy cost to the many stakeholders is also typically ignored or considered only after deployment.

Maybe it can be combined with GPS for better accuracy, too.

Re:Why not GPS

[Errandboy of Doom]

If you're surrounded by wireless access points and nobody can tell you where you are, something has gone seriously wrong with society.

Re:Why not GPS

[newend]

One of the points made in the white paper is that you can't always use satellite based systems, i.e. when you are in a building. By using radio beacons you are able to triangulate a position while not having a view of the sky.

Sorry, I should have said "less erratic"

[Create an Account]

Sorry about that.

Malicious?

[Shadow Wrought]

Can this technology be used by third parties for malicious purposes? e.g.- If Tom Cruise finally ses the light and turns on his Masters, would they be able to track him down with this? I mean, forget the government for a moment, do we have to worry about everyone now?

Re:Malicious?

[sdaemon]

as I read it, this is allowing a receiver to listen to nearby signals and determine its own location, NOT for the transmitters to determine the location of the nearby receiver. In short, if you're not putting out a signal, you can't be tracked by it.

For those who WANT to be tracked, amateur radio has a neat little niche called APRS, but that's probably lost on this crowd :)

Re:Malicious?

[krbvroc1]

Can this technology be used by third parties for malicious purposes?

Any technology can be used for malicious purposes. Its the ying/yang of any invention.

Re:Malicious?

[Anonymous Coward]

The entire point of developing a positioning system is to enable "location based services." A device that didn't transmit its location would be useless to telcos, marketers, and governments -- the drivers behind this technology. You can be sure any such device would transmit its location, most likely by cell networks. Law enforcement needs access to that information, so it won't be possible to disable it.

The FCC recently proposed requiring VoIP over WiFi phones to include a location positioning technology, most likely either this kind of WiFi triangulation or GPS, in order serve law enforcement purposes.

Re:Malicious?

[newend]

I imagine you could put a PDA with one of those verizon modems in someone's car, and then it could determine where the person is and everyone once in a while send you an email with the location... Alternatively, it could be possible to create a virus/malicious piece of software for a cell phone that will use the triangulation to determine a location and use SMS to send that information to someone else.

Re:Malicious?

[Anonymous Coward]

The FCC recently proposed requiring VoIP over WiFi phones to include a location positioning technology, most likely either this kind of WiFi triangulation or GPS, in order serve law enforcement purposes.

No they didn't. The FCC recently proposed requiring VoIP providors to provide the locations of their customers, and provide their customers with an easy way (which can just be a website) to quickly update this database with their latest whereabouts. Mass hoards of pseudo-libertarian Slashbots decided to read the summary, put the most idiotic spin on it, and derive from this that the FCC was mandating GPS, etc, technologies to be incorporated in everyone's laptops.

Time code reference?

[dada21]

Sounds interesting. As geeky teens we tried making our own positioning system using 3 transmitters, one receiver and a PC. It never worked well as we didn't know how to properly encode the current time into the 'pings' to calculate the transit time.

Do all these broadcast cells broadcast the time code? Are the clocks in sync or do they need to be? I'm guessing without a way to "time" pings received, there's no easy way to validate your position.

The "need" to find yourself seems sort of a waste for most. GPS is nice but I'm more interested in real time user voting on traffic (on their road, in their direction). GPS + realtime traffic heuristics could offer faster escape routes during evacuations, or better gas mileage by avoiding idle periods.

Re:Time code reference?

[Skadet]

Aren't pings by definition time-stamped?

Ping uses the ICMP protocol's mandatory ECHO_REQUEST datagram to elicit an ICMP ECHO_RESPONSE from a host or gateway. ECHO_REQUEST datagrams (``pings'') have an IP and ICMP header, followed by a ``struct timeval'' and then an arbitrary number of ``pad'' bytes used to fill out the packet.

Re:Time code reference?

[dada21]

Network protocol pings are. Radio transmissions might not be.

The 'ping' our attempt made was merely an analog "beep" on a given frequency, with 3 differences frequencies. Had we incorporated digital time coding instead of just a beep, we could have triangulated properly. Too bad we had no clue about that.

Re:Time code reference?

[Skadet]

Or, if you could have ensured that the beeps were being emmitted at precisely the same time, you could have worked out a way to calculate where you are given the lag in receiving the beeps

Received frequency and relative time:
Freq2: 0
Freq1: +0.0023
Freq3: +0.0001
Then you correlate that to a spot on your triangle-looking map and viola! Maybe. I think the kid in me likes to try and come up with ways to make kid experiments work.

Re:Time code reference?

[MWelchUK]

I'm guessing without a way to "time" pings received, there's no easy way to validate your position.

It is likely that rather than "pinging" the landmarks it is often sufficent to list those points which you are within range of and which you aren't. Even better is to provide Signal Strength information about each landmark. Iterative solution algoithms can then be used to approximate location to a good degree of accuracy based on this information.

GPS + realtime traffic heuristics could offer faster escape routes during evacuations, or better gas mileage by avoiding idle periods.

GPS is nice, however it suffers in heavily built up/covered areas (such as cities and woods) due to relections and attenuation of signals. GPS really falls down indoors - it usually completely stops working. I think this work is largely targeted towards context aware/ubiquitous computing

Re:Time code reference?

[Morgalyn]

If they work off of multiple pings, the broadcast signals do not need to have their clocks in sync - the deltas from each source could be used to estimate distance.

Re:Time code reference?

[CaseyB]

The triangulation here is based on relative signal strength, not on time differences like GPS.

There's no way you could do this with the time difference. Even with GPS, where the transmitters are tens of thousands of kilometers away, you need nanosecond-accurate clocks to be able to make sense of the differences in timing. With the transmitters only a block or two away, you haven't got enough difference to work with.

Re:Time code reference?

[kevlar]

Your method would never work anyways because you need an atomic clock in order to get the accuracy needed for useful GPS. The formula is as simple as Rate * Time=Distance for the speed of light to travel from the beacon to the device, however you need the time to about 6 or 7 decimal places to measure any actual distances.

There are some tricks that allow your GPS device to have an accuracy of an atomic clock (since the GPS satelite has an atomic clock), but I'm not sure the same trick could be applied for other beacons broadcasting time in microseconds.

Re:Time code reference?

[dada21]

Ahh, signal strength correlation would seem possible.

It seems like a huge amount of work. Why not just pay a few media companies to transmit a time coded ping and base location on that? Trying to keep abreast of tower location changes is a huge waste of manpower, IMO.

Re:Time code reference?

[dada21]

Delta time? You can only know the time delta if you know the time it was sent and the current time.

Re:Time code reference?

[LWATCDR]

This could be very useful for robotics and even for as you put it context aware computing.
Finding a location to within a few inches in a building could be very useful. Imagine going to a conference and having your PDA guide you to the conference room. Or the correct gate at an airport.

Re:Time code reference?

[Morgalyn]

Well, if you use the time specified in the first ping, and the time specified in the second ping, you have two times... with a difference between them.

Re:Time code reference?

[EvilTwinSkippy]

The tricks the GPS use are perfectly applicable for a terrestrial installation. The only caveat is that you will need contact with at least 4 towers for he math to work out. You are right, microseconds is too course a resolution to work out a position. You really need time in nanoseconds.

Or you just need to switch to ultrasonics. The speed of sound propagation in air is on the order of hundreds of miles per hour, instead of hundreds of thousands.

Re:Time code reference?

[RovingSlug]

GPS satellites are far away for geographic coverage. Your assertion should probably read:

Even with GPS, where light still travels at about a foot per nanosecond, you need nanosecond-accurate clocks to be able to make sense of the differences in timing.

Re:Time code reference?

[KFury]

With the transmitters only a block or two away, you haven't got enough difference to work with.

Actually, it has to do with the clock accuracy, not the distance of the transmitters.

The spatial resolution of GPS has nothing to do with how far away the beacons are. Only the 'correctness' of the beacon position and the synchronicity of the timecodes matter. Of course atmospheric interference and signal bounce also come in to play, which is why more sources are better and why ground-based DGPS is more accurate than sat-only GPS.

Re:grammar police!

[Anonymous Coward]

Even if you write them at the daddypants email they still leave it up that way. Why do we have editors here anyways?

Before and after

[Skadet]

Before: This Intel-written whitepaper introduces an determine their locations...
After: This Intel-written whitepaper introduces a way to determine location...

I really thought I had suddenly become retarded and couldn't parse english anymore. Thankfully, and quick edit proved me wrong.

Really wierd to see revisions as they happen on the front page.

Re:Before and after

[Arbin]

I really thought I had suddenly become retarded and couldn't parse english anymore. Thankfully, and quick edit proved me wrong.

Uhh...

Re:Before and after

[Anonymous Coward]

"I really thought I had suddenly become retarded and couldn't parse english anymore."

Whew, I am so glad you have those fears too.

After long hours of coding, comprehending English sometimes makes me start feeling like Santa's- Little-Helper listening to Homer

Huh?

[sdirrim]

Didn't we used to call this wardriving?

Re:Huh?

[sdirrim]

Oops, never mind. But couldn't this be hacked to determine where a given person is at any time? They better have tight security on this!

Re:Huh?

[Anonymous Coward]

There's no place like 127.0.0.1

There's no place like localhost? Perhaps you mean "There's no place like ~"

Re:Huh?

[216pi]

did anyone mention plazes yet?

Plazes is a grassroot approach to location-aware interaction, using the local network you are connected to as location reference. Plazes allows you to share your location with the people you know and to discover people and plazes around you. It's the navigation system for your social life and it's absolutely free.

Re:grammar police!

[DustyShadow]

Ha modded redundant!! Sorry but you can't be redundant if you are the first to point something out!

What's the deal with GPS on cell phones?

[swb]

OK, this is kind of off-topic, and I realize the idea is that cell phone companies want to charge you for everything, but...what's the deal with the GPS/location thing on my phone?

Why can't they tell me where I am on that thing using the same info they'd send to 911? I'm not even sure the "Get it Now" payware applications can access it.

It just seems like such an obvious extension of the cell phone, especially since they've already added the location technology.

Re:What's the deal with GPS on cell phones?

[iwsmith]

I am no expert, but I think the reason they have GPS is this: Some cell phones use a time modulation technique to fit multiple users on a small frequency range that was allotted to them. This technique involves shifting parts of your signal in the sub-microsecond range (I dont actually know how fast the shifts occur), and as such require very precise timing (if not the tower and phone would not be in sync I suppse). GPS is the most logical way to achieve this, as GPS sat's transmit the current time as well (each GPS sat has an atomic clock on board). So, they use GPS to get extremely accurate times, which are then used for what I can only describe as their 'ninja-foo' signal manipulation to fit many users in a rather limited frequency space.

Re:What's the deal with GPS on cell phones?

[Mr2001]

Check your phone's service menu. On my LG, I can get there by pressing Menu-0-000000. There's probably a test screen you can use to check your GPS information.. if the towers in your area support it. Note that not all positioning information is available on your phone - the tower plays a big part in finding your location when you use E911.

Re:What's the deal with GPS on cell phones?

[Anonymous Coward]

"the GPS/location thing on my phone" IS "the same info they'd send to 911." Without it the best fix they could get on your phone location in an emergency is the cell tower serving you. Location services were mandated by law to enable 911 functionality. (ostensibly, there are further uses, some billable, some 'sinister') GPS is only one of the location technologies proposed in response.

Re:What's the deal with GPS on cell phones?

[CXI]

Um, I don't think any of that is correct. Towers have GPS receivers to get accurate time signals, but they can transmit this to the phone, so the phone doesn't need a receiver of its own.

http://3w.gfec.com.tw/english/service/content/gps_ ec.htm

Re:What's the deal with GPS on cell phones?

[rnelsonee]

The scheme you describe is TDMA (time-division multiplexing algorithm), and it was in use before everyone went to CDMA/GSM. Anywho, IIRC (that's a big if), the time signal was sent from the cell tower, and GPS-level accuracy wasn't needed. Each phone that operated TDMA off of a tower was assigned a time slot when the call was initiated and simply kept it's own time internally and it worked well enough because microprocessers had no problem keeping millisecond timings correct for a couple of minutes.

Re:What's the deal with GPS on cell phones?

[mkartha]

The "GPS/Location thing" on your phone _is_ intended to provide these types of Location-Based Services (LBs) both for e911 purposes and for consumer network services.
The issue here is rollout timing. Currently, most mobile carriers are scrambling to meet their FCC e911 obligations. Eventually the carriers will definately roll out LBS to consumers, once e911 is satisfied and they have a billing model to profit from the service.

The consumer mobile phone location services that you want are similar to the e911 services mandated by the FCC but there are some fundaemental differences which I'll attempt to describe:
There are two phases of e911 (http://www.fcc.gov/911/enhanced/); some of this data is summarized by mobileIN on one page here: http://www.mobilein.com/wireless_emergency_service s.htm
Phase I: (required by April 1 1998)
provide emergency service responders at the local Public Safety Answering Point (PSAP) with the callback cell phone number and the location of the connecting tower a mobile emergency call.
Phase II: (commence Oct 1 2001 - complete by Dec 31 2005)
requires wireless carriers to provide far more precise location information of an incoming mobile emergency call, within 50 meters 67% of the time, within 150-300 meters 95% of the time.

The Phase II e911 requirements give some leeway to the wireless carrier as to how this location service is provided: handset-based, tower/network-based, or a hybrid of the two.
As of Oct 1 2001, all new handsets sold in the US had to require e911 Phase II capabilities to assist with e911 location services. This is the service your phone has and that's what the symbol implies. Some phone manufacturers may have even made this information reasonable easy for a consumer to access (I think another thread refers to an admin code for an LG phone).
Apparently by Dec 31 2005, all active handsets must supply e911 compliant services or will be denied wireless carrier service.

Regardless, the e911 Phase II services are the priority for the wireless carriers and lays the foundation for further mobile LBS applications.
Note that the e911 requirement is that location information be provided to the the PSAP - a fairly simple requirement given that the carriers have full control of how they provide this information.
Mobile applications will require a sophisticated, robust API to access this location data, which must be maintained by the carrier - in most cases the carriers just havn't done it yet.
Prior to the buyout by Cingular, AT&T had apparently rolled out Location services for beta-testing in Seattle WA (as early as 2002) and it is likely that Cingular is benefiting from the AT&T expertise.
Now that phones are being made with fast cpus and gobs of memory, it's quite possible to do the GPS math in the handset if you have access to the connection information in sufficient detail.
Nokia Series 60 phones and above make this information available via the handset API and I know of at least one Nokia app that can track which tower you are attached to. Once you know the tower, it is a simple question of
"is this tower's location in your database?"
If so, the software knows the handset is within x radius of the that tower - ie you know where you are well enough to coarsely locate the phone.

I believe what this Intel whitepaper proposes is the similar recipe on a broader scale.

1. Setup an good receiver/antenna
2. Receive all radio signals across all frequencies well enough to parse the unique tower code, Radio station ID, or MAC address in the case of Wifi access points.
3. Use the vast location database of all known radio signal transmitter beacons to locate all sources of the signals received
4. Use this combined information to perform a triangulation with a massive number of known points and cancel out beacon location errors; even without timing data, trian

Re:What's the deal with GPS on cell phones?

[Mr2001]

GSM uses a time modulation technique, but it's been around since before phones had GPS capability.

The grandparent (a Verizon customer) uses CDMA, which also predates phones with built-in GPS receivers. It does depend on having accurate time at the towers, though, which GPS is useful for.

Re:What's the deal with GPS on cell phones?

[Mr2001]

GSM also uses time slots.

GPS

[requim]

I say just add a built in gps receiver to each wap that is sold and have it store it's position information and make it available some how. Obviously there are atleast two problems with this method that would still need to be solved.

1. Any pre-gps device or any device that is not a wap (ie a wireless nic that is acting as a wap) will not have the positioning information. This could be overcome with a set of known points that could identify the position/locality of the pre-gps/rogue device.

2. GPS position could be spoofed/poisoned. This could also be solved by having a set of known equipment that has a position verified by gps.

Re:GPS

[Ion Berkley]

Or it could just be that GPS doesn't work indoors or in urban canyons....how many AP's are placed outside with a clear view of the sky???

Direct Download Links

[theGreater]

Sorry, I don't have a torrent hosting setup -- someone else want to grab these?

• Windows XP (and probably 2000)
• Linux
• Mac OS X
• Generic (no scripts)

  -theGreater.

Network pings, yes...

[Anonymous Coward]

Network pings are named after the more traditional sonar ping, though. What the poster above you was saying is that he and his teen buddies had trouble timestamping the signals their transmitters were putting out. He and his friends were trying to do a transit time based triangulation, so this information was pretty critical.

On the other hand, I don't think the timing information in a computer is really precise or reliable enough to do a timing based calculation. Certainly you wouldn't rely on the timing of four million independent devices to be synched. This intel system seems to work on signal strength.

Sounds similar to Psiloc's miniGPS

[bigtrike]

This sounds very similar to Psiloc's miniGPS, except with the addition of additional sources and a location database.

http://www.psiloc.com/index.html?action=ShowArticl eItem&ida=154

The resolution from a single GSM tower seems to be within a mile or two. You can use it to trigger actions on your phone when you get in a certain area. If phones were capable of tracking signal strengths of other towers (I assume they do in order to be able to handoff) you could do this much more accurately. Mapping that into coordinates is fairly tough however, which would make Intel's database very useful. It would probably be far easier to pay the cell carriers for their tower location/code databases though.

I guess there should be a clue in there somewhere

[marcus]

Think a moment....

Prior Art

[ngr8]

Interesting article. Couple of observations: Triangulation doesn't require time, just imputed direction. http://www.loran.org/library.html has some interesting resources. Cellular location services at http://www.binspy.com/tech/lbsvs.html get a little further along. Also, whilst being able to ride on a lot of different "antennas", seems that one could get to an arbitrarily precise location in two (if not three) dimensions. (For example, the car is at (x1,y1) according to the FM stations, and the 802.x gets it down to a circular error probable of x1+/- 1 meter, y1+/- 1 meter.... ok mongo, throw the egg!)

Re:Prior Art

[jumpingfred]

Triangulation does however need directional antennas which most things do not have. More than that they need accurate directional antennas those are complicated and expensive.

Herecast

[Anonymous Coward]

This sounds very similar to what was done by this student (http://www.herecast.com/) a few years ago.

Re:Herecast

[tijmentiming]

Yeah, we had a similar project at school a year ago. I had some e-mail conversations with him about bluetooth positioning.

Local Database?

[TheRaven64]

Why not use DNS? If each of these wireless devices has its own IP address, why not make the reverse lookup contain the geodata (it's not like the required fields aren't already in the DNS spec, after all). Then the standard system resolver can handle the caching for you.

Re:Local Database?

[nietsch]

It sounds like a nice solution at first, but you have to rely on the AP or Cell tower to have a unique IP. That will not be the case, as AP (until IPv6 if fully accepted and implemented) usually act as NAT router too and have a local network adress. Can you locate 192.168.1.1 for me please?

The article mentions mac numbers or celltower ID's that have to be linked to a location. Maybe you could resolve those locations with a DNS-like system, but I am sure there are more eficient ways to do that.
A complicating factor is that the devices cannot rely on continuus net acces, so the lookups need to be queued until acces is available. And since they aim for handheld devices, you can assume the storagespace is restricted, making all the other fields that come with DNS not only useless but unwanted too.
I can see you recently had a DNS-hammer in your hands, but this does not look like a IP-lookup nail, sorry.

Re:I guess there should be a clue in there somewhe

[DustyShadow]

I'm not sure if you noticed, but the first sentence was all jacked up when the article was posted. I didn't expect my comment to be modded up. Offtopic was a better mod than redundant.

Most useful in doors- factories, etc.

[cbelt3]

C'mon- take off the tinfoil hats already. This tech is already active in some places, primarily as a tracking tool for indoor industry. Here's an example:

Your company makes big widgets that get pushed around your factory floor on carts. You want your people to have the flexibility to push the carts where they need to go, but at the end of every shift carts are 'lost', the second shift guy has to go looking around for the half-assembled widget with the missing frannistan.

You can make everyone log their widget work into widget wherezit workstations, but the workers wont want to waste valuable beer time for that. So the widget wherezit workstation logging project fails.

So instead you put a wifi device on each cart. It reads where it is based on the location of access point antennas you've put up in your rafters. It then uses these AP's to periodically tell a server where it is. End results ? You know where your widgets are hiding all the time. Without anyone having to do anything.

I wish /. readers wouldn't be so anxious to find the 'evil government / corporate / wal-mart' "Threat" before they see the real world solution to real world problems.

Besides, the aliens who overthrew the gummint in the 50's already put chips in all your fool heads anyway...

Re:Most useful in doors- factories, etc.

[LaCosaNostradamus]

Automated tracking of ANYTHING related to a costing activity will be analyzed eventually in order to evolve a use of force against workers. If there's any organization we should not condone having overall greater tracking power, it's the Fascist power of the corporation.

Your personal finances are often scrutinized and therefore held against you for things not related to them, namely rental lodging and employment. Factories are closed and moved simply because a spreadsheet says so, and those numbers are the result of increasingly denser analysis environment. So who's wearing the fucking tinfoil hat here? I think it's YOU, and the tinfoil's been pulled over your eyes, in your denial of the abuses that inevitably follow more pervasive surveillance technology.

Anything invoked for surveillance should be roundly criticized for invasion of privacy and overall good sense. From that, regulations must occur if We The People are to retain our Human rights and dignity in all places, public and private.

In the example you offered, the locators for the carts should be restricted by at least the regulation that such data be "location display" only, and not be logged so that some fuck in a suit can use their movement as leverage against worker productivity.

Tinfoil that, you fuck.

Re:Most useful in doors- factories, etc.

[el americano]

So instead you put a wifi device on each cart.

Of course you mean, put an RFID on each cart. Choose the right technology for the right task. The Wi-Fi locatator is intended for you to passively read radio beacons and compute your location at the receiver. You're requiring the receiver to have the computing power to collect the info and report it back to a central location. It's a makes for an expensive receiver and it wastes your Wi-Fi bandwidth. Better to have RFID sensors, then use that to track your widgets, all your other inventory, your workers...

Re:Most useful in doors- factories, etc.

[quentin_quayle]

Whether it's good or evil simply depends on one thing: whether it's optional for the device owner.

If it's wired into the hardware such that the device owner can't use the device without reporting his location, it's evil. That means "capable of abuse", and in practice, human nature being what it is, "capable of abuse" means "will be abused to the maximum extent by whoever has the power to do so"; and that in turn means "will be abused to the maximum extent by government and corporations to exploit individuals".

On the other hand, if it's an optional feature that the owner can use or not use, as he/she chooses, then it's good.

You see, it's really simple. No tin foil hat, just facts and reason.

Re:Most useful in doors- factories, etc.

[Anonymous Coward]

Just RFID? Why not add medical sensors to help keep the employees safe? That way employers can know if someone is in danger and immediately send them aid. Just think of the possible scenario: alarm goes off, seems two employees Ms. Hottotrot and Mr. Studmuffin are local storage area B4IP experiencing slightly higher body tempertures, excellerated heart rates and labored breathing, better send the rescue teams in. Course if this happens in a germ warfare reasearch facility, forget the rescue team, seal gas and irradiate, oh heck just set off the nuclear cleanup device automatically.

AP in my backyard

[Anonymous Coward]

I have a small tower serving as an AP for a local ISP (free net for me, yeehaw).

Does this mean that a bunch of geeky yahoos (not to be confused with yeehaws) are going to be trespassing up my hill to get a fix on the antenna position?

If so, can I mow them down with my cantenna?

Other Arts: E911, LORAN, Hybrid Triangulation

[ngr8]

Couple of observations:

Triangulation from fixed points does not require a time stamp, just directions.

Some other sources:
- Cellular Location Services (E911, drive by text ads...) some discussion at http://www.binspy.com/tech/lbsvs.html

- LORAN at http://www.loran.org/library.html

Arbitrary Precision
Having spent all of a minute to thing about this, wouldn't a multi-band/multi-protocol gizmo give the ability to find location in 2-space (if not 3-space) to an arbitrary level of precision? Example: the FM station signal locates the car in (x,y) with a circular error probable of 200 meters. AM station signals reduce it to a CEP of 10 meters (waves hands a lot now), and the radar leaks from airports reduce it to 2 meters....) Made up gedanken example, but it does seem feasible to me, gentle /. readers.

I can see it now:

[heavy snowfall]

On the front page of the NY times: INTEL releases sweet new wardriving HACK!

--
Considering linux? Distro guide

Other Art: Cellular Location/LORAN/Miscellaneous

[ngr8]

Couple of observations:

Triangulation from fixed points does not require a time stamp, just directions.

Some other sources:
- Cellular Location Services (E911, drive by text ads...) some discussion at http://www.binspy.com/tech/lbsvs.html

- LORAN at http://www.loran.org/library.html

Arbitrary Precision
Having spent all of a minute to thing about this, wouldn't a multi-band/multi-protocol gizmo give the ability to find location in 2-space (if not 3-space) to an arbitrary level of precision? Example: the FM station signal locates the car in (x,y) with a circular error probable of 200 meters. AM station signals reduce it to a CEP of 10 meters (waves hands a lot now), and the radar leaks from airports reduce it to 2 meters....)

Made up gedanken example, but it does seem feasible to me, gentle /. readers.

E911, cellular position identification

[1zenerdiode]

Many of these efforts have been underway for years as the cellular providers have developed infrastructure to prepare for E911 positioning requirements. Various schemes have been proposed including usage of terrestrial radio sources such as TV, radio and wireless networking. The more practical approaches use TDOA (time-difference of arrival, similar to triangulation, only using ranging info instead), or brute-force with GPS receivers.

"Someones Comes to town...."

[haplo21112]

This sounds like something right out of the Cory Doctorow Novel. I say if they ever try to claim a patent, he has the Prior art all locked up.

You are 220 meters North of "Linksys"

[wsanders]

Puts new meaning to "no matter where you go, there you are..."

Re:You are 220 meters North of "Linksys"

[HermanAB]

Whenever I do a scan I get several linksys boxes and all on channel 6. If only Linksys had the sense to make the default channel random - sigh...

Re:I guess there should be a clue in there somewhe

[marcus]

I don't mind the grammar police. Education and diligence are both good things. I have been a volunteer GP myself. I thought it funny that you were surprised by 'redundant' since you certainly are not the first to point out poor sentence structure on /.!

Onward!

Re:Other Art: Cellular Location/LORAN/Miscellaneou

[ngr8]

My bad... got a "couldn't find server" followed with a "couldn't find post". Hangs head, cries.

this was done before at etech 04

[enrico_suave]

I believe some folks set up/cobbled together a similiar setup with 802.11 at O'Reilly Emerging Tech 2004 conference. (it's linked somewhere in there ;) )

e.

Useful How?

[camt]

Huh? So I can use a database of various RF transmitters to determine Where In The World I Am? But I usually already know where *I* am. It would be more interesting to know where the radio beacons are (but then, I could just look those up in the database).

What I want to know is where I can get software that displays a map of where access points are in relation to my laptop - a la the software that comes with the new Toshiba tablets.

Re:Useful How?

[a-singularity]

Huh? So I can use a database of various RF transmitters to determine Where In The World I Am?

Not so you know where you are, but so the device knows where it is. Think localized services for mobile network enabled devices. Adverts, sales, movie times, local interest info...

Place Lab isn't a particularly new thing and using the wifi access points isn't terribly accurate. Your calculated position has a tendency to 'jump' as much as 100 feet in the Place Lab system.

Re:Useful How?

[camt]

Not so you know where you are, but so the device knows where it is. Think localized services for mobile network enabled devices. Adverts, sales, movie times, local interest info...

Ah so!

But isn't GPS a better technology for this?

Re:Useful How?

[drewzhrodague]

Check out http://www.WiFiMaps.com. We've got a connector for AvantGo, which will let you use that to download maps of your area, and APs in that area.

Re:Useful How?

[AcidFnTonic]

I'm actually writing custom wardriving software that will provide this functionality for linux....

basically you hook up a gps to your laptop, grab a mappack of the area, and it plots what is known from wigle.net
it also functions as a kismet client if you feel like finding some of your own. It will plot what you find and optionally let you save the new aps to wigle.net email me at acidtonic -=At=- acidtonic (dot) homedns (dot) org for more info.

Can I use this to find dna-paterniti-testing?

[ugmoe]

Can I use this to find the nearest dna-paterniti-testing location and a place to redeem my free Applebee's dinner for 2?

Re:Can I use this to find dna-paterniti-testing?

[EvilTwinSkippy]

Not until you reactivate your Paypal account after the fradulent activity that was recorded as coming from...

Hasn't this Been Done?

[Sux2BU]

How is this different than the "Locate Me" option in Virtual Earth? Granted it only works with 802.11, but does having GSM and Bluetooth in the mix even help?

Rosum - TV signal positioning

[Ion Berkley]

All very old hat and late to the game. Most of these signals that Intel talks about are less than ideal. The real deal is the broadcast TV signals, especially the new DTV ones. 1MW of power and 6MHz of bandwidth per NTSC channel makes for some good positioning signals to work with. The company you are looking for is ROSUM (www.rosum.com) who has been doing this for some time

Navizon is already doing this

[DHR]

they have a working client for pocket pc pda/phones. http://navizon.com/

Re:Navizon is already doing this

[Johngreennyc]

Yup. I tried Placelab and it didn't do it for me. It was very unstable and it was just not working. I installed navizon on my PDA and after running their install wizard, I was up and running. Plus they have a neat feature where you can find cool places (bars, restaurant, etc...) around you. A very cool app that I strongly recommend. And no, I don't work for them, but they did a really nice job and someone should say it.

Auto channel selection?

[ThJ]

Does anyone know why access points even -have- fixed channels? If I can install Kismet on my Linksys WAP54G and scan for access points, can't the access point itself do the same, and put itself on the first free channel with the least noise on it? Wireless NICs scan the channels anyway, so I don't see why this isn't feasable.

Re:Auto channel selection?

[HermanAB]

The better ones do. Industrial grade APs have many more features than commercial grade junk.

Re:Auto channel selection?

[ThJ]

AP manufacturers would save -sooo- much money on customer support if they automated features such as these.

Re:Auto channel selection?

[Anonymous Coward]

Not really, they would lose money on the industrial grade stuff because the comercial grade stuff is good enough. I wonder if a linux ap could do this for free.

Re:Auto channel selection?

[ThJ]

I think the WAP54G firmware could be modified to do this. It's open source, after all.

Bluetooth positioning

[drewzhrodague]

Perfect use for that old bluetooth-enabled phone. Plug it in, put it somewhere, and you've got a location beacon.

Re:Bluetooth positioning

[Anonymous Coward]

Oh my, you're so smart. Have my babies, dickweed.

www.plazes.com

[krokodil]

And www.plazes.com is building initial database of such beacon point locations. It could have some pretty cool uses, provided that privacy concerns are adequately addressed.

Re:www.plazes.com

[EvilTwinSkippy]

And www.plazes.com is building initial database of such beacon point locations. It could have some pretty cool uses, provided that privacy concerns are adequately addressed.

Most of the applications that come to my mind require that privacy concerns haven't.

}:D

Wardriving is cool!

[drewzhrodague]

Of course, I am quite biased, but Wardriving is cool!

And what do you do with wardriving data? Plot it on a map, of course. This is fun, but not that much fun. When you can use that kind of data for other interesting purposes -- like finding out where you are -- then things get interesting.

This is not a new technology, though I guess I should have pattented this in 2002 when I had a chance. Damn that unemployment line!

Why not GPS - so the US can't turn it off

[markdowling]

At present, the US can degrade the quality of GPS or turn it off for military reasons. This was one motivation behind the EU and Russia wanting their own systems, so they weren't depending on American whims. A distributed series of wireless points, especially on a device supporting 802.11 and wireless like the Blackberry 7270, removes the dependence on satellites but does introduce uncertainty as to the accuracy of the mapping of the access points - trying to trace the physical location of an IP address largely depends on trusting the admins who are entering the location of the routers along the way.

Re:Other Art: Cellular Location/LORAN/Miscellaneou

[Anonymous Coward]

LORAN used a time stamp, or at least a reference time, from the chain master signal. The location was calculated from the time differences between the master signal and all the slave transmitters. Except in L.A., where the master/slave terminology is considered politically incorrect.

Isn't this extremely imprecise?

[autophile]

From RTFA, I can't tell... are they just saying that the presence or absence of a signal determines your location? Like saying, "Oh, I'm getting WINS on the radio. I must be within 200 miles of NYC"? I was kind of hoping for a precision of at least one foot, if not better.

--Rob

Query Mapper "Linksys"

[Anonymous Coward]

select count(*) from mapper where beacon_id like "Linksys"

(45036953 rows returned)

The deal is it doesn't work

[jeffmeden]

GPS receivers will have to come a long way before they will be capable of picking up enough usable signal from your pocket to trilateralize your location, AND do it all in a power-friendly package. GPS positioning in phones is hype, the only way to get a reliable location is through tower triangulation.

Re:Other Art: Cellular Location/LORAN/Miscellaneou

[EvilTwinSkippy]

Actually, I don't know why they are bothering with 802.11 and blue tooth. You have stations broadcasting at thousands of watts from fixed locations. They can be detected for hundreds of miles in every direction. Why not key off of commercial FM, AM, and Television stations?

Granted, broadcast stations in different markets do use the same signals. And in many markets many of the broadcast towers are in one or two locations. (I.E. TV hill.) But with a little creativity, and a few manually keyed bits of data (like what city you are starting in) you could put something together.

My thought is to use a quad of diversity antennaes to give a rough sense of direction, tied to a database of FCC licensed broadcast towers with Lat/Long coordinates.

Radio Geeks, what is a good design for a direction finder? Preferably solid state.

Problem with the system

[Anonymous Coward]

The problem with this system is that is seems to assume perfectly spherical propagation of the radio signals (see TFA for reference to Venn Diagrams). Any good HAM can rattle off many factors that influence propgation. A few that come to mind: aluminum siding, atmospheric effects, hills.

One of the things that makes GPS so percise is that the algorithms can use additional satellites (above the minimum 3 required for a surface fix) to estimate the propogation errors through the ionisphere. I have no idea how you'd do that world wide for the type of transmitters being discussed. There are digital terrain models for the hills, but I doubt all the building construction materials used are available.

Not to mention the inaccuracies with the current mapper data noted in the article.

Microsoft uses this technology

[Anonymous Coward]

Microsoft is using this type of technology in their Virtual Earth website, as reported on Channel9.msdn.com. If you click on the Locate Me button, it gives you the option to download a little app to triangulate your position based on hotspots, or to find your location based upon your ip address. Nothing new here...

google

[Itanshi]

can this be combined with google maps? I saw someone mention msn, but well :-P

So I take it

[hey!]

that this is not what they're talking about?

Applications are already using this

[Anonymous Coward]

There is a short list of applications that are already using this. Most notably Skyhook Wireless, Meetro and Active Campus.

an interesting application

[Anonymous Coward]

Nice. Now if your notebook is stolen, it can determine its own location and email you with that information. Having it check a specific email address for a predetermined "Notebook, you've been stolen!" message alerting it to the fact would be a trivial startup task.

Basic Localization problem

[Morticae]

I've done this before. In a city it works great. It's a very basic localization problem that comes up in robotics. Basically, with a dense enough population of wireless routers (most uniquely named) you can run algorithms which "localize" your position. It can actually work extremely well in a city where there are many devices. Even if some of them change, the beauty of the system is that it can easily prune/add new nodes while functioning normally.

RFID vs WiFi

[cbelt3]

RFID has its uses. RFID has a major defect in an operationally chaotic installation. The defect ? Ya gotta route the chip-carrying widgets past RFID readers. RFID is Passive technology. It isn't capable of saying "Here I am! Come get me !" without prompting. It requires a handshake and proximity.

RFID is applicable tech for tracking of mid to low value items. For high value items (like shipments of missles and nukes, for example), an active monitor is required. That's why you see active monitors on a lot of trucks nowadays- GPS receiver and cell phone or packet radio communicating location periodically.

Cost, bandwidth, and computing power are not a significant issue with a periodic query/call approach. Set the units to randomly compute their location and connect / communicate / disconnect, and you've got enough bandwidth for a cloud of thousands of the little buggers.

As far as cost is concerned, well, if your materials have enough value, you can justify a $100 tracker. Just like RFID, the initial cost of tech was high, and once you got volume, savings would accrue. From a component perspective, you could get out the door for the cost of a pretty nominal cell phone.

Oh, and Mr. tinfoil ? Sheesh, man, amp up the Lithium. You've obviously gone off your meds. You're like those suburban mom eco-nazis who yammer on about pollution and eating meat while driving their SUV's and wearing leather coats. I bet you LIKE the evil corporate UPS's tracking tools when you bought your comp from another evil corporation. Dude, you're just helping oppress your fellow carbon based lifeforms by using those tools of corporations, right ? Isn't that what you're saying ? Do us all a favor, be true to your philosophy. Stop using anything that comes from a corporation. We'll enjoy the silence on this end...

Re:RFID vs WiFi

[el americano]

From rfidjournal.com:

What is the read range for a typical RFID tag?
The read range of passive tags (tags without batteries) depends on many factors: the frequency of operation, the power of the reader, interference from metal objects or other RF devices. In general, low-frequency tags are read from a foot or less. High frequency tags are read from about three feet and UHF tags are read from 10 to 20 feet. Where longer ranges are needed, such as for tracking railway cars, active tags use batteries to boost read ranges to 300 feet or more.

That could work just fine in a warehouse with multiple receivers.

Yes, done before

[Anonymous Coward]

http://virtualearth.msn.com/ - click the 'locate me' link in the header. it uses wifi AP's to determine location. If you have WiFi, it is accurate often to 100 feet or so. if not, it falls back to a far less accurate IP address location lookup