How can Google Maps accurately locate my phone when GPS is disabled?

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Closed 7 years ago.

Possible Duplicate:
How does Google Maps estimate my location without GPS?

I was wondering how Google Maps on my Android phone can locate me with a good accuracy when my GPS is disabled.

At first I though it was with the cell tower but I'm not sure it can achieve this precision and it is way better when the wireless is enabled.

Experiment that i did.

1. If GPS is OFF and Wifi is ON = Perfect location



2. If Wifi is ON GPS OFF = Still Perfect location


3. If Wifi is OFF and GPS is ON = location is not precise.

Tested this with 5 -6 Phones

Any Idea why ?