This depends on the application: If you want to perform simple GPRS tests and just want to verify that GPRS is working, then the 4261 GPRS Go/NoGo Option will do. If you want to perform more thorough testing and want to really stress the phone, then you need to go for the 4262 GPRS Measurement option. Please note that you need the GPRS Go/NoGo Option in any case since this is the pre-requisite for the GPRS Measurement Option.
