GSM? CDMA? TDMA? What does it all mean?! How can I tell what I have?

Ok, quick guide to help you learn the differences between all the confusion with GSM and CDMA (and yes, even TDMA) phones.




Cingular uses a technology called GSM (Global System for Mobile Communications). GSM phones use a SIM Card(Subscriber Identity Module Card). A SIM Card stores information such as the user’s phone number, phone book as well as other information related to the subscriber and the carrier of the mobile phone. Cingular and T-Mobile are the most common providers in the US


Simcard^^


Sprint uses a technology called CDMA (Code Division Multiple Access). This is a purely digital network. Transmission from the phone goes to a radio/router type device, digitalized into a series of coded numbers. Sprint and Verizon are the most common CDMA carriers in the US.


CDMA explination ^^


Basically, to tell the difference between the two, look around the phone for a SIM Card. If there is no SIM Card slot, it is a CDMA. If it's a Nextel or Boost phone, it's called TDMA*. No, it's not compatible any GSM or CDMA carrier.


*TDMA (Time Division Multiple Access) - A digital wireless transmission that allows a large number of users to access one radio frequency without acctually interupting service. It uses a "Time Slot" technology, meaning, it's like a call center ("A representative will take your call in the order in which it was recieved").


Example^^