GPRS signal quality

Hello,
My customer has some kind of mobile phone that shows GSM signal strenght and GPRS signal strenght seperately. He says that sometimes Gprs signal is very poor while Gsm signal is excellent. Can it be possible?
How can i query the signal quality of Gprs service rather than querying of Gsm signal with AT+CSQ?
Thanks.

IS it a dual-SIM phone?

GPRS uses the GSM RF signal - so the signal strength cannot be different.

Are you sure that he is correctly interpreting the phone’s display? Ask for a copy of the phone’s handbook where these features are described…

Customer says that his phone displayed “no GPRS signal” message but full rate of GSM signal. He also tested it. He called me by his phone and we could talk properly. Just after that, he tried to connect to GPRS but he couldnt! He says his phone displayed “no GPRS signal” when he had tried to connect to GPRS. This made me confused.
I think he uses a “Push to talk” type of mobile phone.

GPRS is an “overlay” on top of GSM - so it is possible that “basic” GSM could be available, but GPRS not available.

Remember that phones are made for non-technical users - so they may use terminology that isn’t entirely precise.