Global System for Mobile Communications
The Global Systems for Mobile Communications (GSM), is a radio-based technology that allows mobile phones to communicate. GSM is considered to be the world's most ubiquitous radio-based cellular technology, with 1.7 billion users as of March 2006. In the United States, carriers such as T-Mobile and Cingular utilize GSM technology for their cellular networks.
GSM Cell Phone Providers
GSM is considered to be 2G and uses digital data for both signaling and voice purposes. GSM uses a time division multiple access (TDMA) protocol to transmit information. Aside from voice, GPRS and EDGE allow for data transmissions across a GSM network.