Global System Mobile, GSM , 2G
Alexander Kukushkin · 2018
The main part of standardization of the Global System Mobile (GSM) system was conducted in the European Telecommunications Standards Institute (ETSI) Special Mobile Group (SMG) until 2000 and since then by the 3rd Generation Partnership Project (3GPP). The GSM network can be split into three subnetworks: the radio access network (RAN), the core network and the management network. There are physical and logical channels in GSM radio system. GSM provide ISDN services on the fixed side in addition to a number of specific services, named GSM specific services, including: global roaming (initially Pan-European), authentication (fraud control), ciphering (speech, data, signalling) and user confidentiality (ciphered subscriber number on-air-interface). The in-call signalling performed using two control channels, Slow Associated Control Channel (SACCH) and FACH. The symbol rate over the radio channel and the primary TDMA structure are chosen as a result of a compromise between acceptable transmission performance over the worst specified propagation channel and implementation/cost limitations.