Global System for Mobile Communications (GSM)

Global System for Mobile Communications (GSM) is a second-generation digital mobile telephone standard (2G) using a variation of Time Division Multiple Access (TDMA). Of the three digital wireless telephone technologies (GSM, TDMA, CDMA) it is the most widely used with 90% of market share as of 2014. It was developed by the European Telecommunications Standards Institute (ETSI). Later generations (3G UMTS and 4G LTE) are not part of the ETSI GSM standard.