Originally Posted by jswinden
Not really, A-GPS typically has a lower grade GPS chip, which makes a difference, and uses cell towers to look at cached data which is a bit older than what the GPS satellites can provide. It is predictive tracking.
You are wrong.
An aGPS system has two separate functions.
The first is a traditional GPS satellite system, that works that same as other GPS systems.
The second is a cell-tower based system, which is used when GPS lock has not been achieved.
It is true that cellphones generally have smaller, poorer, antenna than dedicated GPS units, but that has nothing to do with the aGPS function, it is a hardware difference.
These devices can be used as GPS units with no SIM cards installed, so no cell connection.