What is GSM? Is it different than normal cell phone service? How do I know if I have GSM or not?
GSM is a type of digital mobile phone service. The more common type of digital mobile phone service in the US is CDMA, but just about every other country in the world uses primarily or only GSM. For you as the user of your phone, there is no difference at all between using a phone on a CDMA system or a phone on a GSM system. Unfortunately, the two different systems are not compatible with each other. If you have a T-Mobile, Cingular, or recent new M-mode type service with AT&T, then you have GSM service. Will my existing cell phone service provider know if I unlock my mobile phone We’re not sure about this. Certainly, if they physically have your phone, they can get it to display its current lock status, but when you have the phone, we’re not sure. It might be possible, in theory, for them to interrogate the phone through the cell service control signals, and get the phone to advise of its status, but we’ve never heard of this being done.
