OK! Thanks to Sreejith's link, the picture is getting clearer. Google's geolocation API provides an single interface over a variety of geolocation techniques. It uses IP based, wifi based, cellular based and GPS based geolocaton - whichever is available, may be even multiple ones. This API may soon become a W3C standard and a standard part of every browser.
As regards to wifi geolocation, there is a huge database of wireless APs and their location. They create this by wardriving. They drive a car around the city with a GPS receiver and a wifi station. Whenever a wifi AP is found, its BSSID and GPS location are entered into the database. Later when users want its service, it sends a list of all visible BSSIDs to the database. The database returns reasonably accurate location- may be upto 20m. This is crudely similar to triangulation, but technically it is not triangulation. As for cellular geolocation, I think they use the same technique. Instead of BSSID, they use CellID. I don't think they use triangulation. I remember that GSM data frame has slots for multiplex synchronization, but don't remember seeing any timing information. So triangulation may not be the method- though it seems more plausible than wifi triangulation. Thanks for all the help and info everyone! Now I can see where it is going and appreciate its potential. Regards, Gokul Das --~--~---------~--~----~------------~-------~--~----~ "Freedom is the only law". "Freedom Unplugged" http://www.ilug-tvm.org You received this message because you are subscribed to the Google Groups "ilug-tvm" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For details visit the website: www.ilug-tvm.org or the google group page: http://groups.google.com/group/ilug-tvm?hl=en -~----------~----~----~----~------~----~------~--~---
