Saturday, 3 May 2008 21:32:03 - by : admin

Before GSM technology announced, there are several wireless communications in the world. The first implementations of radio waves for communication were realized in the late nineteenth century for radiotelegraphy. Since then, it has been a widely used technique for military communications.
After Second World War, the real two-way public mobile radio communication systems took place with electronic techniques such as the vacuum valve enabled the implementation of real-scale telephony service for car. The first true mobile telephone service was officially born in St Louis (Missouri, USA) in 1946. Europe, recovering from war, followed as a few years later.
Between 1950 and 1980, mobile radio system evolved to become automatic and the costs decreased due to the introduction of semiconductor technology. During 70's, large-scale integration of electronic devices and the development of microprocessors open the door to the implementation of more complex system.
The cellular concept was introduced by Bell Labs, and was studied in various places in the world during 70's. In US 1979, the first cellular system, the AMPS (Advanced Mobile Phone Service) was announced. In Sweden 1981, the NMT (Nordic Mobile Telephone) was started which aimed at Scandinavian coverage.
Networks based on these two set of specifications account for the great majority of mobile networks throughout the world in the early 90's. TACT derived from AMPS was put in service in the UK in 1985.
Due to the limitation of existing analog system and the incompatibility between TACT and NMT by mean a TACT terminal cannot access the NMT network and neither can a NMT terminal access a TACT network, so the new concept with new standard which using a common bandwidth and common standard was needed.
The CEPT (Conference Europeenne des Postes et Telecommunications) is a standardization area  which – in the early 80’s – included the European Administrations of Posts and Telecommunications of more than 20 countries.
The new standardization body within CEPT was introduced in 1982, whose task was to specify a unique radio communication system for EUROPE at 900 MHz. The new born "Groupe Special Mobile(GSM)" held its first meeting in December 1982 in Stockholm, under the chairmanship of Thomas Haug, from the Swedish Administration. 31 person from 11 countries were present at the first meeting.
In 1990 by request of the United Kingdom, the specification of a version of GSM adapted to the 1800 MHz frequency band was added to the scope of the standardization group, which a frequency allocation of twice 75 MHz. This variant referred to as DCS1800 (Digital Cellular System 1800) is aimed at reaching higher capacities in urban areas for example for the type of mass-market approach known as PCN (Personal Communication Network).
The year to year process is shown bellow.


 Source : The GSM Communications by Michael Mouly & Marie-Bernadette Pautet

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