Some Operation Gadget readers may already know that AT&T Wireless has decided to rebuild its U.S. mobile phone networks that run on the 850-megahertz radio frequencies to use the GSM protocol. The so-called GSM 850 system is not compatible with most GSM phones already on the market here.

O'Grady's PowerPage published a handy guide to U.S. mobile carriers and the network technologies they use. The article really focuses on GSM-based carriers: T-Mobile, AT&T Wireless, and Cingular. That's particularly helpful at the moment because the GSM part of the market is where confusion is likely to take place in the near future.

If you are the kind of person who chooses their wireless carrier based on whether they support the phone that you want to buy, you need to know something about each carriers' networks. This is a good way to get some basic knoweldge. [ via canikickit.org ]