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Forget GPS, Hello WPS
No France writes "A company known as skyhook wireless has announced the commercial availability of its Wi-Fi Positioning System, or WPS. The company has compiled a database of every wireless access point it can find in a given city. When a mobile user running th Skyhook client is in a recorded area, their position is calculated by selecting the surrounding signals and comparing them to the reference database. Currently there are 25 US cities mapped, including New York City, Boston, Chicago, Los Angeles and San Francisco. Apparently this device is accurate to within 20-40 meters, though one has to wonder how well it deals with people moving their wireless access points."
20 - 40 meters? Who will be forgetting GPS with that kind of crappy accuracy?
. . . but I suspect ultimately of little practical value. Having done quite a bit of RF scanning on the WiFi bands in one of their listed cities (San Francisco) I've seen first hand how signals behave in that dense urban environment.
GPS and WAAS operate on time signals and highly accurate positioning. Cell towers would be inherently more accurate since thier positions are accurately known and don't change (except under very unusual circumstances.
WiFi nodes come up and down constantly, and their position is rarely going to be accurately known by anyone but the person who installed it - and chances are they're not telling "you" exactly where the node is.
Given "walk around surveying" to map the nodes, it's not really a surprise they have accuracy that's no better than an early 2 channel GPS receiver.
And, as others have pointed out, if I'm in downtown San Francisco (or any other city) I don't need my GPS to tell me I'm at 5th and Townsend. For directions there's Mapquest, Google, Yahoo Maps, etc...
Interesting technology. But it sounds more like something a hobbiest would come up with than business.
Never attribute to malice what can as easily be the result of incompetence...
To be honest, I don't care how novel their ideas are. Using a system where position is located based on such arbitrary measurements is not only silly, but a waste of time. Not only can anyone move the access points around, but as they get shut off or more get added it will only make things worse. Also considering it can be influenced by minute things like weather and the position of the microwave in the apartment across the street make it a waste of time. You'd need to rescan it at least monthly to maintain even 20-40 feet (screw that) accuracy.
Let's see, a near-absolute positioning system based on immobile and unchanging (or extremely slowly) data, or something based on what could probably be described as a chaotic system? Not to be a jerk about it, but "Forget GPS"? More like "Ignore WPS".
"What do you despise? By this are you truly known." --Princess Irulan, Manual of Muad'Dib
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Yes, but my iPaq has Wi-Fi not GPS. And the screen can show a good map.
I could ensure I'm always carrying a GPS reciever or just a city map but you know what, I own both these and only carry them when I know I need them. Which in the case of GPS, is never.