A:Answer As Listed in the Specifications: AT&T, T-Mobile, Cricket, TRACFONE, Net10, Simple Mobile, H2O Wireless (Basically All GSM Based Networks) CDMA is Owned by Qualcomm, In the US, Sprint, Verizon and US Cellular use CDMA. AT&T and T-Mobile use GSM. Most of the rest of the world uses GSM. The global spread of GSM came about because in 1987, Europe mandated the technology by law, and because GSM comes from an industry consortium. Unless you are contracted to a CDMA provider, GSM is the better direction.