What Is The Difference Between CDMA And GSM?
CDMA Carriers (Sprint, Verizon, Alltel, Metro Pcs, Qwest, US Cellular, Helio) don’t require Sim cards to have wireless service, but instead use the phones Electronic Serial Number (ESN). GSM carriers (AT&T, T-mobile, Movistar, Telcel,) have SIM Cards (Subscriber Identity Module cards) that the phones use to communicate with cellphone towers. The two are complete opposites of each other.
