AT&T coverage map

Carriers operate under one of two types of networks: CDMA or GSM. Out of the four biggest carriers with their own network, AT&T and T-Mobile run on GSM , while Sprint and Verizon Wireless use CDMA.

AT&T and T-Mobile use GSM networks for all their cell phone service, and Tracfone cell phones that use GSM run off of one of those two major carriers (mostly AT&T). CDMA stands for Code Division Multiple Access and is less popular world wide, but more popular in America.

All unlocked phones work on carriers that use GSM networks . Popular U.S. carriers that use GSM networks include AT&T, T-Mobile, Cricket, MetroPCS, Simple Mobile and Tracfone. Most foreign carriers also use GSM networks. You will need to use a SIM card from a GSM provider to get service for your unlocked phone.

Great questions! We use CDMA . The network is America’s largest, most reliable 4G LTE, with the most reliable hotspots.