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GSM -
> What is GSM?
During the early 1980s, analog cellular telephone systems were experiencing
rapid growth in Europe, particularly in Scandinavia and the United Kingdom, but
also in France and Germany. Each country developed its own
system, which was incompatible with everyone else's in equipment and operation.
This was an undesirable situation, because not only was the mobile
equipment limited to operation within national boundaries, which in a unified
Europe were increasingly unimportant, but there was a very limited market for
each type of equipment, so economies of scale, and the subsequent savings, could
not be realized.
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The Europeans realized this early on, and in 1982 the Conference of European
Posts and Telegraphs (CEPT) formed a study group called the Groupe Spécial
Mobile (GSM) to study and develop a panEuropean public land mobile system.
The proposed system had to meet certain criteria:
- good subjective speech quality,
- low terminal and service cost,
- support for international roaming,
- ability to support handhald terminals,
- support for range of new services and facilities,
- spectral efficiency, and
- ISDN compatibility.
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In 1989, GSM responsibility was transferred to the European Telecommunication
Standards Institute (ETSI), and phase I of the GSM specifications were published
in 1990. Commercial service was started in mid1991, and by 1993
there were 36 GSM networks in 22 countries, with 25 additional countries having
already selected or considering GSM . This is not only a European
standard - South Africa, Australia, and many Middle and Far East countries have
chosen GSM. By the beginning of 1994, there were 1.3 million
subscribers worldwide . The acronym GSM now (aptly) stands for
Global System for Mobile telecommunications.
The developers of GSM chose an unproven (at the time) digital system, as
opposed to the thenstandard analog cellular systems like AMPS in the United
States and TACS in the United Kingdom. They had faith that
advancements in compression algorithms and digital signal processors would allow
the fulfillment of the original criteria and the continual improvement of the
system in terms of quality and cost. The 8000 pages of the GSM
recommendations try to allow flexibility and competitive innovation among
suppliers, but provide enough guidelines to guarantee the proper interworking
between the components of the system. This is done in part by
providing descriptions of the interfaces and functions of each of the functional
entities defined in the system.
Courtesy John Scourias
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