Global System for Mobile communications is the most popular mobile phone standard. According to the GSM Association, which represents the interests of the global mobile communications industry, about 80 percent of the world uses GSM technology for wireless voice calls.
CDMA vs GSM: What's the Difference?
Below is a brief overview of some mobile providers that use GSM:
GSM offers broader international roaming capabilities than other U.S. network technologies and can make a cell phone a "world phone." With GSM, switching SIM cards activates multiple phones on the same network account. In addition, GSM allows simultaneous data and voice operations, something CDMA cannot do.
GSM carriers offer roaming contracts with other GSM carriers and typically offer better coverage in rural areas than competing CDMA carriers. Often there are no roaming charges involved.
