What Is GSM in Cellular Networking?

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-Mobile
• AT&T
• Indigo Wireless
• Pine Cellular
• TerreStar

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.

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.