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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."
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.
Sorry, I don't have a torrent hosting setup -- someone else want to grab these?
-theGreater.
This sounds very similar to Psiloc's miniGPS, except with the addition of additional sources and a location database.
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http://www.psiloc.com/index.html?action=ShowArtic
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.
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!)
Verizon: Latin for "poor rural service".
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
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 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
This sounds very similar to what was done by this student (http://www.herecast.com/) a few years ago.
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:
/. 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.
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
Besides, the aliens who overthrew the gummint in the 50's already put chips in all your fool heads anyway...
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.
Couple of observations:
/. readers.
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
Verizon: Latin for "poor rural service".
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...).
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.
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.
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http://3w.gfec.com.tw/english/service/content/gps
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
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.
This space is intentionally staring blankly at you
they have a working client for pocket pc pda/phones. http://navizon.com/
The private company is Skyhook Wireless
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They hit the front page in June.
http://hardware.slashdot.org/article.pl?sid=05/06