What is GPS on a phone?

[BigMrChimps]

I have seen many threads here with questions on how the GPS on the phone works. Many of the answers that were given were complete bunk. When you think of GPS everyone immediately thinks of the satellites that are in space all over the globe that help to locate your position. There is another system out there that your phone uses. It is the system of towers that each cell phone company has in place all around the country. The cell phone is able to triangulate its own position from the varying strengths of signals it picks up from the towers around itself; it is able to judge from the individual names of the towers its exact coordinates on the globe. This system was put in place tagged with saving lives for 911 purposes. When you dial 911 the device automatically sends its coordinates to the authorities in order that emergency services will be able to find you quicker.
GPS without having service, Now to answer that thread if you were able to use the gps functionality of the device to work before or have it working now, for VZW customers DO NOT UPGRADE THE SOFTWARE VERSION. Sorry for the caps but it is important if you would like the phones GPS to keep working. The GPS functionality is disabled by some cell phone companies if you do not have service.
Hope this helps!