POSITIONING METHODS:

Phones that are capable of using GPS (Global Positioning System) will have several different methods of positioning. You can select which positioning methods you use by going to Menu> Tools> Settings> General> Positioning> Positioning Methods.

(1) Integrated GPS - This refers to a phone's built in GPS receiver. GPS satellites continuously transmit their location relative to the Earth, and your phone's GPS receiver can calculate its own position if it knows the position of at least three satellites. Today, almost all N- and E-series phones have integrated GPS, plus a selection of 6xxx phones.

(2) Bluetooth GPS - If you do not have integrated GPS or you wish to improve GPS reception, you can connect your phone to an external GPS receiver device which can replace or complement Integrated GPS.

(3) Assisted GPS - This is a network-based service used to help fix a GPS position. When using this, small amounts of data are transmitted so you need a network-based internet service from your network operator for which you may be charged by the download volume. Only small amounts of data are involved, but you should take care using this feature if you are travelling outside your own country as roaming data charges can be high.

(4) Network-based - whenever your phone is switched on and in range of your operator's network, it knows which base station (commonly known as the transmitter or mast) it is connected to, and using that information it can approximate your position using this network data. This is an additional help in obtaining a GPS fix, and it also makes a brief data connection.

(copy from beginning of this thread)