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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.