I’ve had a little more success in getting the new location feature of Google Maps Mobile working.

From home I had a location to within 1700m (which is pretty much the whole village). Oh well, perhaps the whole village is supplied by one powerful cell (unlikely, I suspect). No location on the train travelling in. It found my location again when I reached Cambridge station. Again to 1700m. Hmmm. There must be plenty of cells around there. I wondered whether my phone was just sticking to a distant cell, so turned it off and on hoping it would pick up the nearest cell. No location.

Mobile cells don’t transmit location information to the device (a telecoms engineer onced explained why to me, I evidently wasn’t sufficiently convinced to remember the explanation!). To get a location you need two things: the cell id and a database of cell ids against locations. Since I’m getting occasional locations that indicates that the database is sparse for Cambridge.

I wonder how Google’s database of cell locations is built up? From the help system:

“Google takes geo-contextual information [from anonymous GPS-readings, etc] and associates this information with the cell at that location to develop a database of cell locations.”

“Anonymous GPS-readings etc”? Location expert Andrew Grill has published an in-depth analysis of the location feature, and did a small experiment to find that Google’s database is built from GMM users with GPS enabled devices. So for me to get decent location information I need someone with a GPS enabled Orange phone running around Cambridge running GMM. Presumably the location will be some kind of average of the observed location-cell id points, so I’ll need a horde of Orange-GPS-GMM folks. Volunteers?

I’m completely unsurprised that the networks didn’t just give Google cell location information, and it seems this kind of social approach to building location services has been tried at least once before, using custom software on the phone.

Couldn’t Google accept user input within GMM to build the database faster? I know where I am (most of the time), and I’d be happy to center GMM on my current location and click “Here I am” to help build the database. I bet I’m not alone.

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