The GSM network (Global System for Mobile Communications) is a standard of mobile phone on the digital platform. It’s a real revolution in mobile phone system that comes with GSM network in the second generation (2 g). GSM technology reduced the costs and increased the number of mobile communications, contributing to the spread of the mobile phone as a consumer product. The GSM network was designed in the late 80s by the French group Groupe Spécial Mobile, hence initially also the acronym GSM, and subsequently adopted by the European Telecommunications Standards Institute (ETSI) in 1989 to write specifications of commercial mobile networks.
Since 1998 the development of the specifications of the GSM network is done by concorzio 3GPP (3rd Generation Partnership Project) that also participates in the ETSI. The GSM network has allowed us to introduce interoperability between different networks, which can communicate with each other by following a standard size fits all digital Protocol. The adoption of the GSM network extends in Europe in the 90s, replacing previous first generation mobile radio systems to progressively (i.e. TACS). Thanks to digital communication, GSM network can effectively use data compression and source coding (LPC) information, greatly increasing the throughput. Communications are also much safer because the digital platform enables you to use encryption techniques of communication. Among the novelties of GSM deserves to be underlined the ability to send text messages (SMS) between cellular devices, a feature initially underestimated by the designers, and the ability to exchange data in digital format (GPRS, EDGE, etc.) between phones. With GSM network spread the SIM card (SIM card) which allowed to separate the phone from the phone number itself. The SIM card contains only the identification form SIM (Subscriber Identity Module) which allows the network to recognize a user’s cell phone and pair it with your phone number. The radio signal covers the territory through the presence of cells and radio stations, 900 and 1800 Mhz radio band using a (Dual Band) in Europe, Usa, South America and Asia, 850 Mhz and 1900 Mhz in North America. This aspect limits phones compatibility as you move from one continent to another. A technological limit fixable by purchasing special phones Tri Band or Quad Band.