IN THIS REPORT
•	Cell phones: Overview
	•	CR Quick Recommendations
	•	Ratings
	•	How much phone do you need?
	•	Design details
	•	GSM network troubles
•	Calling plans: Overview
	•	The bottom line
	•	Cost, then minutes

Trouble in the GSM network

Cell-phone systems in Europe and Asia generally use the same digital network technology: GSM, for Global System for Mobile Communications. In the U.S., however, GSM is only one of four digital technologies in use. T-Mobile uses it exclusively, while AT&T Wireless and Cingular are building a GSM network alongside their older one, which uses TDMA technology. Both carriers plan to offer new data services only on GSM. But the change is creating problems for current AT&T and Cingular customers.

One problem is coverage. The two carriers’ GSM networks don’t appear to provide the same coverage that TDMA customers get. An AT&T spokesman told us that the two networks mostly coincide, but he concedes that “there could still be Bermuda triangles where you get coverage on one but not the other.” A look at AT&T’s map of coverage in North Carolina (see illustrations below) shows how different the two networks can be. With GSM, the home calling area is smaller and thus, the roaming area is larger.

Another problem, which we encountered in our testing, affects the Sony Ericsson T62u phone sold by Cingular. It uses a multinetwork technology that’s designed to provide the best possible coverage on Cingular’s TDMA and GSM networks. The T62u that we purchased for testing worked well for a while, then could no longer pick up a GSM signal. Even though we had the help of Cingular store clerks and customer-service personnel, exchanged the phone for a new sample, and obtained a new phone number, the T62u continued to work erratically.

What you can do. If you’re planning to switch to AT&T or Cingular, choose the phone carefully. Some phones, such as the recommended Siemens (12), also work on the more-extensive TDMA network, bettering the odds that you’ll get service (see table below). Four of the tested GSM-only phones have what’s known as 850/1900-MHz capability, a feature mentioned in stores and ads, that should offer better coverage nationwide as the GSM networks grow. Cingular offers other multinetwork phones, such as the T62u; if you choose one, take advantage of Cingular’s trial period so that you can exchange it if it doesn’t meet your expectations.

If you’re a long-standing AT&T or Cingular customer using the TDMA network, sit tight. You can continue to use the phone you have for the foreseeable future.

North Carolina-TDMA		North Carolina-GSM
On the AT&T maps above, orange represents the home calling area--a much larger territory on the TDMA network than on the current GSM system. For AT&T’s or Cingular’s coverage in your area, check the carrier’s Web site.

	Phone	Backup
12	Siemens S46		•
13	Panasonic GU87
14	Siemens S56	•
15	Nokia 3595	•
16	Nokia 6800	•
17	Nokia 3650
18	Sony Ericsson T616	•

For more information on this topic and many others, subscribe to ConsumerReports.org.

Copyright © 2004 Consumers Union of U.S., Inc.