A public all-digital cellular network using TDMA techniques for multiplexing and using a transmission band around 900 MHz. GSM formerly identified the Groupe Speciale Mobile of the European Telecommunication Standards Institute (ETSI); today it is a worldwide standard. A GSM network can provide, besides telephony services, short messaging services (SMS) and data communication, in circuit- and/or packet mode. GSM signaling uses specific channels and protocols; voice is compressed at about 13 kb/s and error correcting algorithms (FEC) are used. The core network is based on a 64 kb/s circuit-switching technology. A more recent version uses an 1800 MHz band; modern terminals currently used in Europe can access both networks depending on traffic conditions and other parameters. A GSM version using a 1900 MHz access network is available in the United States.