Could you please explain in more details your use case as I do not understand what exactly you want to do with GPRS and why you mix together GPS and GPRS.
If you are using Android then you should use Google play services for getting locations. In order to improve accuracy you can also make sure that you have implemented a function where it receives updates on location signal.
I would like to ask if it possible to have both GPS and GPRS in function. Does wikitude work only with GPS? Is it possible to make changes in this part?