How does the position determination work with the GPS device?

How does the GPS module provide its position determination?

The GPS module in a smap uses the so-called Assisted GPS (A-GPS for short) to determine the position: 

A-GPS adresses the problems of conventional GPS, for example, by utilizing the GSM mobile network to transmit auxiliary data to the receiver in order to significantly improve the succession timespan of positional determination. 

 Source: Wikipedia