I have a good understanding A-GPS functionality. I understand that assisted GPS is used to improve TTFF, works better indoors but costs more as you are using the mobile networks to determine the position.
Let's say you have a simple PCB with a GSM module and a GPS module. Both modules use an antenna.
Is it possible to fully do without the GPS module and the antenna and purely rely on the GSM module to determine the position using assisted GPS? By any chance is this what smartphones do? I understand that GSM antennas come in many different shapes and sizes, but are less affected by physical mass between the antenna and the mast. However, the GPS antenna needs a clear view of the sky in order to determine the position.
If my device is going to be used indoors mostly, would I not be better off completely scrapping GPS and just using the assisted GPS functionality of the GSM module?