init. grams per square metre, (unit for measuring the weight of paper)
GSM (Global System for Mobile Communications, originally Groupe SpécialMobile), is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile phones, first deployed in Finland in July 1991. it has become the default global standard for mobile communications - with over 90% market share, operating in over 219 countries and territories.
2G networks developed as a replacement for first generation ( 1G) analog cellular networks, and the GSM standard originally described a digital, circuit-switched network optimized for full duplex voice telephony. This expanded over time to include data communications, first by circuit-switched transport, then by packet data transport via GPRS (General Packet Radio Services) and EDGE (Enhanced Data rates for GSM Evolution or EGPRS).
Subsequently, the 3GPP developed third-generation ( 3G) UMTS standards followed by fourth-generation ( 4G) LTE Advanced standards, which do not form part of the ETSI GSM standard.
"GSM" is a trademark owned by the GSM Association. It may also refer to the (initially) most common voice codec used, Full Rate.
GSM is a European standard for mobile phones.
GSM may also refer to: