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Wireless Positioning

Posted by CmdrTaco on 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."

5 of 133 comments (clear)

  1. Time code reference? by dada21 · · Score: 5, Interesting

    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.

  2. What's the deal with GPS on cell phones? by swb · · Score: 4, Insightful

    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.

    1. Re:What's the deal with GPS on cell phones? by iwsmith · · Score: 4, Interesting

      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.

  3. Direct Download Links by theGreater · · Score: 4, Informative

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

  4. Most useful in doors- factories, etc. by cbelt3 · · Score: 4, Informative

    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...