CDMA vs GSM: The Two Main Types of Digital Cellphone Systems

It's worth talking a little about the two different systems used in North America, as this should be an important factor in your decision when choosing a cellphone service provider. There are essentially only two different cellphone systems, with many different providers, in North America: GSM and CDMA (see glossary for more info).

If you have a CDMA phone, your provider will have a roaming agreement with all other CDMA providers, so as you move around North America, you can use your phone seamlessly as you are switched automatically from one CDMA provider to the next (eg Sprint, Telus, Bell). The same goes for GSM phones (eg ATT, Rogers): you can move between any GSM carrier for continuous coverage.

In fact, GSM is the global standard in perhaps 90% of the world, so you can roam all over the globe with it (CDMA is mostly North America only). We spend our winters in Mexico, and Mexico is mostly GSM, which is another reason I wanted to keep a phone that works on GSM.

This ability to move around between carriers is called roaming and it works well, but be prepared to pay up the wahzoo for usage if you are roaming.

The problem is, CDMA does not work with GSM (and vice-versa), so if you want maximum coverage, you need a phone and account to use on both networks. I already had an HTC Touch phone running on GSM with Rogers (which I was paying through the nose for), so what I was looking for was a Touch phone running on CDMA. Note: Sprint has recently unveiled a phone from Samsung that handles both GSM and CDMA networks, although it wouldn't suit my purposes.

NEXT: Bell Gets My Business