Global System for Mobile Communications
The GSM network was developed in response to a need for a system, which could be used all over Europe and would allow its users to receive and make calls from a number which was not attributable to any geographical area. The GSM system was designed to also enable the customer to be billed by just one operator and pay for only one line rental.
GSM is the most widespread mobile system and is now used by more than 50% of the phones worldwide, which was largely as a result of early standardisation by the European authorities. It is available in over 170 countries, although there are now four different frequencies upon which it operates; 450, 900, 1800 and 1900MHz.
