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Everywhere you go, there you are

I've been playing with the beta build of Google Maps for Mobile on a couple of different phones (a Blackberry and a Windows Mobile device) and different networks, and I have to say - it's looking pretty decent. The biggest change is a good one, with the introduction of My Location. It's a definite "does what it says on the tin" feature, as it uses a database of cell tower locations to show you where you are, within a kilometer or so. That's enough to get you located, and able to use the mapping tools to find exactly where you are.

I've found it a lot more accurate than the stated error, usually getting me within a street or so of where I am (and as it doesn't use GPS, I can use it indoors or in the Tube). I've used cell location tools before, and this is by far the best and most accurate. Some place you at random places on the map, while others just fail to have decent UK databases.

Here's Google's own YouTube whiteboard animation of My Location in action:



So, are there any quibbles? I'd like it to support Google Maps new terrain feature, but I suspect that the build cycles are out of sync here - especially as the terrain view came out around the same time as the latest build of GMM...

Comments

( 7 comments — Leave a comment )
celestialweasel
Dec. 6th, 2007 09:36 pm (UTC)
But how does it really know where you are? Is there a Java API call that returns the tower number, or what?
sbisson
Dec. 6th, 2007 09:45 pm (UTC)
Generally it's a phone OS level function - and depending on how it's implemented it'll give you the timing offset and ID of the nearest tower.

It's known as TOA (Time Of Arrival), and can be used to give a distance from the cell tower. A more accurate (but not as common) version uses up to three cell towers to triangulate. I suspect that Google is using TOA rather than ETOA.
celestialweasel
Dec. 6th, 2007 10:01 pm (UTC)
So is GMM a Java applet? I thought this sort of useful info was the sort of stuff that J2ME didn't let you get at.
sbisson
Dec. 6th, 2007 10:16 pm (UTC)
It varies - on Windows Mobile it's (AFAIR) C++, and on Blackberry it's working with RIM's own Java APIs.
celestialweasel
Dec. 6th, 2007 10:20 pm (UTC)
Ah, I see. I certainly had a Symbian app which told me the tower number (before the phone disintegrated and I decided I didn't need a 'smart' phone).
twinfair
Dec. 7th, 2007 09:39 am (UTC)
And, new visitor to Tottenham Court Road, if you do not have this feature on your phone, use the old fashioned method: stick your nose in the air and smell out that elusive curry house. I know people who would track a curry house quicker than any phone could! :)
sbisson
Dec. 7th, 2007 09:51 am (UTC)
I have to admit my first thought was: "TCR? You don't want to go there. Now Charlotte Street, that's a different curry story!"
( 7 comments — Leave a comment )