GSM vs. CDMA
The highs and lows of two major, international cellular network technologies
Last reviewed: July 2009
Major carriers use one of two network technologies, GSM, for Global System for Mobile communication, or CDMA, for Code Division Multiple Access. Most phones are designed for one or the other, and each technology has characteristic strengths.
In general, GSM phones—used by AT&T and T-Mobile—provide more talk time on a battery charge, typically five hours and up. They also are better for exchanging photos and other data with computers and other mobile devices without going through the wireless network. Many GSM phones with Bluetooth capability can wirelessly swap their address book with other phones or beam photos directly to a printer or photo kiosk. And because GSM is more widely used across the world than CDMA, many phones sold in the U.S. will work in Europe and Asia. But no GSM phones have the analog backup needed for times when the digital network is inaccessible, as in some rural areas.
CDMA phones, which are used by Sprint and Verizon, use higher-speed data networks. Most provide analog backup. They're also more likely than GSM phones to have historically useful features, like a standard, 2.5 mm headset connector.
Nextel, which merged with Sprint in 2005, uses a proprietary network technology that's incompatible with CDMA and GSM.
Posted: June 2007
