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Wireless Networking Hardware

Wireless Positioning 133

Posted by CmdrTaco from the just-crazy-enough-to-work dept.
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."
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Wireless Positioning More

Wireless Positioning

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  • 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?
  • [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.

    • 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 [wikipedia.org] of whitepapers.
    • 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.
      • 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...).
  • 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? (Score:3, Informative)

      by sdaemon ( 25357 )
      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 :)
    • 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.

    • 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.

  • Time code reference? (Score:5, Interesting)

    by dada21 ( 163177 ) * <adam.dada@gmail.com> on Tuesday October 04, 2005 @10:54AM (#13713294) Homepage Journal
    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.

    • 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.
      • 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.
        • 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.

      • Network pings, yes... (Score:1, Interesting)

        by 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

    • 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 ro

      • 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.
      • 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.
    • 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? (Score:3, Informative)

      by CaseyB ( 1105 )
      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.

      • 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.

      • 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 t

    • Re:Time code reference? (Score:3, Interesting)

      by kevlar ( 13509 )
      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
      • 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.

  • Before and after (Score:2, Interesting)

    by Skadet ( 528657 )
    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.

  • Huh? (Score:3, Funny)

    by sdirrim ( 909976 ) <sdirrim @ g m a i l . com> on Tuesday October 04, 2005 @10:55AM (#13713311) Journal
    Didn't we used to call this wardriving?

    • Re:Huh? (Score:3, Insightful)

      by sdirrim ( 909976 )
      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!
    • On the front page of the NY times: INTEL releases sweet new wardriving HACK!

      --
      Considering linux? Distro guide [arpx.net]
    • Of course, I am quite biased, but Wardriving is cool! [wifimaps.com]

      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!
    • did anyone mention plazes [plazes.com] 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.

  • What's the deal with GPS on cell phones? (Score:5, Insightful)

    by swb ( 14022 ) on Tuesday October 04, 2005 @10:58AM (#13713349)
    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? (Score:4, Interesting)

      by iwsmith ( 844319 ) on Tuesday October 04, 2005 @11:28AM (#13713623)
      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.
    • 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.
    • 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 e91
    • 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.

  • GPS (Score:2, Informative)

    by requim ( 174679 )
    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 positio

    • Re:GPS (Score:2, Insightful)

      by Ion Berkley ( 35404 )
      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 (Score:5, Informative)

    by theGreater ( 596196 ) on Tuesday October 04, 2005 @11:02AM (#13713386) Homepage

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

  • Sounds similar to Psiloc's miniGPS (Score:3, Informative)

    by bigtrike ( 904535 ) on Tuesday October 04, 2005 @11:09AM (#13713451)
    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 [psiloc.com]

    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.

  • Prior Art (Score:3, Informative)

    by ngr8 ( 504185 ) on Tuesday October 04, 2005 @11:09AM (#13713457) Journal
    Interesting article. Couple of observations: Triangulation doesn't require time, just imputed direction. http://www.loran.org/library.html [loran.org] has some interesting resources. Cellular location services at http://www.binspy.com/tech/lbsvs.html [binspy.com] 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!)
    • 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 (Score:3, Informative)

    by Anonymous Coward on Tuesday October 04, 2005 @11:13AM (#13713482)
    This sounds very similar to what was done by this student (http://www.herecast.com/ [herecast.com]) a few years ago.
  • 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? (Score:4, Informative)

      by nietsch ( 112711 ) on Tuesday October 04, 2005 @12:08PM (#13713966) Homepage Journal
      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.

  • Most useful in doors- factories, etc. (Score:5, Informative)

    by cbelt3 ( 741637 ) <cbelt @ y a h o o.com> on Tuesday October 04, 2005 @11:17AM (#13713511) Journal
    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...
    • 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
    • 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 widge
      • 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

    • 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 individu

  • Other Art: Cellular Location/LORAN/Miscellaneous (Score:3, Informative)

    by ngr8 ( 504185 ) on Tuesday October 04, 2005 @11:22AM (#13713560) Journal
    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 [binspy.com]

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

    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.

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

  • 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.
  • 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.
  • Puts new meaning to "no matter where you go, there you are..."
  • I believe some folks set up/cobbled together a similiar setup with 802.11 at O'Reilly Emerging Tech 2004 conference [oreillynet.com]. (it's linked somewhere in there ;) )

    e.
  • 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.
    • 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.

      • 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?
    • Check out http://www.WiFiMaps.com [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.
  • Can I use this to find the nearest dna-paterniti-testing location and a place to redeem my free Applebee's dinner for 2?
  • How is this different than the "Locate Me" option in Virtual Earth [msn.com]? Granted it only works with 802.11, but does having GSM and Bluetooth in the mix even help?
  • 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

  • they have a working client for pocket pc pda/phones. http://navizon.com/ [navizon.com]
  • And www.plazes.com [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.
    • 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

  • 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

  • that this [midlet.org] is not what they're talking about?

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