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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."
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.
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.
Sony ha
Didn't we used to call this wardriving?
Not only "land of the free" but "land of the lawyers" who love a good old 1st amendment smackdown. Shihar 153932
Procrastination -- because good things come to those who wait.
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.
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.
l eItem&ida=154
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
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...
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".
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.
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...).
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).
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.
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/
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.
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
Zhrodague.net - I do projects and stuff too.
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