World roaming on your cell phone
Before you head off for the airport, there are a few things you should know: Not all cell phones will work abroad, and not all carriers offer roaming coverage in every country. You'll need to find out if you can do it, where you can do it, and how much it will cost. In the pages that follow, we'll answer all those questions to help get you on your way.
Know your technology
Editor's Note: As of November 7, 2012, CNET is no longer updating this story. However, you may find that this article provides general guidance. For specific roaming plans and features, please contact your carrier.
The first step in understanding world phones is to know the difference
between two main ingredients in the cell phone alphabet soup: GSM and
CDMA (see our cell phone buying guide
for more information). In short, GSM and CDMA are the main cell phone
networks in use in the world today. GSM, or Global System for Mobile
Communications, is the predominant global technology and is used in
Europe (where it's the standard), Canada, Latin America, the Caribbean,
Africa, Australia, and New Zealand, as well as much of Asia and the
Middle East. In the United States, AT&T and T-Mobile operate GSM networks.
CDMA, which stands for Code Division Multiple Access, has less worldwide coverage than GSM. One of the biggest markets for CDMA is the United States, where it is used by Verizon Wireless, Sprint, and several smaller carriers such as U.S. Cellular.
Outside of the States, you can find CDMA networks in Canada, Mexico, New Zealand, China, Taiwan, South Korea, parts of the Caribbean and Latin America, and a handful of other countries.