Mobile Phones Android 375 375 people found this article helpful What Is GSM in Cellular Networking? GSM is short for Global System for Mobile Communications by Adam Fendelman Writer Adam Fendelman is a syndicated technology writer and senior web designer whose focus was on web analytics and web design among other things. our editorial process LinkedIn Adam Fendelman Updated on May 26, 2020 Android Switching from iOS Tweet Share Email Global System for Mobile communications is the most popular cell phone standard. According to the GSM Association, which represents the interests of the worldwide mobile communications industry, roughly 80 percent of the world uses GSM technology for wireless calls. Which Networks Are GSM? Here's a quick breakdown of just a few mobile carriers and that use GSM: T-MobileAT&TIndigo WirelessPine CellularTerreStar In the United States, Sprint and Verizon use CDMA instead of GSM. GSM vs CDMA GSM offers wider international roaming capabilities than other U.S. network technologies and can enable a cell phone to be a “world phone." With GSM, switching SIM cards activates different phones to the same network account. In addition, GSM allows for simultaneous data and voice operation—something CDMA cannot manage. GSM carriers offer roaming contracts with other GSM carriers and typically cover rural areas more completely than competing CDMA carriers, and often without roaming charges. What is CDMA and How Does it Work? Technical Information About GSM The origins of GSM start in 1982 when the Groupe Spécial Mobile was created by the European Conference of Postal and Telecommunications Administrations to design a pan-European mobile technology. GSM didn't begin being used commercially until 1991, where it was built using TDMA technology. GSM provides standard features like phone call encryption, data networking, caller ID, call forwarding, call waiting, SMS, and conferencing. This cell phone technology works in the 1900 MHz band in the US and the 900 MHz band in Europe and Asia. Data is compressed and digitized, and then sent through a channel with two other data streams, each using their own slot.