Global System for Mobile Communications
The Global System for Mobile Communications, or GSM1, is the so-called second-generation (2G) cellular mobile phone system. Its predecessors, first generation (1G) mobile phone systems, were analog systems such as the Nordic Mobile Telephone (NMT) system and the Advanced Mobile Phone System (AMPS) . Designers of analog systems did not realize though, that cellular telephony would in a short time become a universal and popular service and thus the systems in question had a rather limited capacity. Moreover, most of them were incompatible with one another, which resulted in serious limitations because users of a given network were exclusively subscribers of a given operator.
The GSM standard was developed thanks to a European initiative aiming at creating a uniform, open cellular mobile phone system. Originally, the standard was to be applied and implemented in the 12 countries of the European Common Market. Accordingly, the European Conference of Postal and Telecommunications Administrations (CEPT) created the Groupe Spécial Mobile (GSM) in 1982 to develop a standard for a mobile telephone system that would operate in the 900 MHz bandwidth . In 1987, a group of 15 operators from across Europe signed a memorandum of understanding in which they agreed to implement the GSM technology to develop a common cellular telephone system across Europe. In 1989 responsibility for GSM was transferred to the European Telecommunication ...