Cell phone buying guide

Pick a cell phone service provider

Buying a cell phone is more than a matter of choosing a handset--you also have to pick a service provider, or carrier, as well. Each carrier in the United States offers a different selection of technologies and services, so it's important to think about your needs when making a choice. For that reason, selecting a carrier should be the first step in the cell phone buying process.

Twisting technology

Wireless carriers in the United States operate over two different networks: Code Division Multiple Access (CDMA) and Global System for Mobile Communication (GSM). Though each technology transmits voice and data, they do so in different ways, which makes them incompatible. As a result, you can't take a CDMA phone and use it on GSM or vice versa.

Of the U.S. carriers, AT&T and T-Mobile use GSM while Sprint, Verizon, and smaller carriers such as such as MetroPCS and U.S. Cellular use CDMA. Though Nextel is part of Sprint, Nextel-branded phones use a third technology called iDEN, or Integrated Digital Enhanced Network.

CDMA coverage is very strong in the United States, particularly in rural areas, but GSM service has a larger global footprint (it's the standard in Europe, for example) and GSM phones use the convenient SIM cards, which you allow you to, among other things, switch phones more easily. Also, when taken on a global scale, GSM users will find a wider selection of handsets.

With that in mind, if you travel overseas frequently or you enjoy switching out your phone often for the newest model available, then GSM is the better choice. Not all GSM phones will work overseas, however, so be sure to read CNET's Quick guide to world phones. But if you'll be making calls mostly in the United States, then CDMA is an equally good option. What's more, some CDMA phones now also support GSM networks for international use.

Besides technology, there are other factors that should play in your carrier decision. You should begin by deciding which carrier has the most economical service plans and the most attractive selection of phones. The quality of customer service is another determinant, but that can be difficult to evaluate beforehand. Since knowing the pros and cons of each operator isn't easy, we invite you to take a closer look at service providers in our Carrier comparison section. Besides the major operators, you might also consider Mobile Virtual Network Operator (MVNO) carriers that cater to a special demographic or lifestyle. For example, Virgin Mobile is targeted toward younger users while Boost Mobile is centered on urban users who want advanced features. MVNOs do not operate their own cellular network, but they lease network space from national carriers instead.

Ultimately though, you should base your decision on which carrier offers the best reception in your area. Because evaluating wireless coverage requires experience with the network in a wide variety of physical locations, CNET does not rate wireless carriers. With that in mind, word of mouth is an essential tool when selecting a provider. Since reception varies sharply by location, ask your friends and family which carrier they use. Also, since there's no substitute for real-world experience, ask to borrow a friend's phone, and test it in your house and your workplace. Remember that carriers have a grace period during which you can test the service and return the phone without voiding the contract. Yet if you do return a phone and cancel a contract, you may have to pay for calls made during the usage period.