Automatic Vehicle Locator

[ayaresr]

I am interested in getting some information on how the avl setup works in a smartzone system. Basically I would like to know is it possible to copy the information from the air and develop a program that will decode it? Is this data present on the control channel or is it part of another transmission? If its available through the control channel, what would be necessary to decode it? I am fairly new at this aspect, but would like to try my hand at writing a program to decode it if possible.
Thanks for the insight,
Ryan