--- On Fri, 3/7/09, Bernhard zwischenbrugger <b...@datenkueche.com> wrote:
> Firefox, iPhone, Blackberry geolocation is a funny thing. > Easy to use. In the case of the BlackBerry browser it pulls the info from a GPS chip if available. Alternatively there is Skyhook Wireless which provide APIs for most "smart phone" mobile platforms. > But how does it work? > There must be somewhere a big database that stores the GPS > locations of > millions of WIFI access points. Mobile phone operating systems usually expose information about the phone network information, that is information on the current base station the phone is connected to. Some operating systems also allow you to find out information about near by cell towers which, phones have this information ahead of time for hand overs etc. There is also the OpenCellID.org project to collect mobile phone tower information. Even without a mobile phone account I think you can get unique identifiers if you have suitable hardware, which is why if you have a suitable phone you can scan for all networks and you will see a list of carriers etc. Back to your question about WiFi, apart from Skyhook Wireless other companies have been building such databases, like Google. _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk