04-12-2012, 05:40 PM
TELECOMMUNICATION SWITCHING AND NETWORK
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INTRODUCTION
Telecommunication networks carry information signals among entities, which are
geographically far apart. An entity may be a computer or human being, a facsimile machine, a
teleprinter, a data terminal and so on. The entities are involved in the process of information
transfer which may be in the form of a telephone conversation (telephony) or a file transfer
between two computers or message transfer between two terminals etc. Today it is almost
truism to state that telecommunication systems are the symbol of our information age.
With the rapidly growing traffic and untargeted growth of cyberspace, telecommunication
becomes a fabric of our life. The future challenges are enormous as we anticipate rapid growth
items of new services and number of users. What comes with the challenge is a genuine need
for more advanced methodology supporting analysis and design of telecommunication
architectures. Telecommunication has evaluated and growth at an explosive rate in recent
years and will undoubtedly continue to do so.
The communication switching system enables the universal connectivity. The universal
connectivity is realized when any entity in one part of the world can communicate with any
other entity in another part of the world. In many ways telecommunication will acts as a
substitute for the increasingly expensive physical transportation.
The telecommunication links and switching were mainly designed for voice
communication. With the appropriate attachments/equipments, they can be used to transmit
data. A modern society, therefore needs new facilities including very high bandwidth switched
data networks, and large communication satellites with small, cheap earth antennas.
HISTORICAL DEVELOPMENT
By the early 1800’s scientists had developed ways to generate and transmit electricity. In
1819, oersted discovered the relation between magnetism and electricity. Ampere, Faraday
and others continued this work in 1820. In 1834, Gauss and Weber wired over the roofs of
Gottingen to make a telegraph system.
Samuel F.B. Morse’s developed the first significant work in telecommunication. F.B.
Morse developed code telegraphy in 1837. In 1844, a 40 mile telegraph line was setup between
Baltimore and Washington by F.B. Morse. In 1845, Morse formed a telegraph company based
on his technology. In 1849, the first slow telegraph printer link was setup. In 1874, Ban dot invented a ‘‘Multiplexes” system which enables up to six signal from telegraph machines to be
transmitted together over the same line.
Elisha Gray and Alexander Graham Bell contributed significant works and filed paper
related to telephony. The early stages of the development of telecommunication were due to
A.G. Bell, G. Marconi and C.E. Shannon. In 1876, Bell invented a telephone system. In 1897
Marconi patented a wireless telephone system. Teletypewriter service was initiated in 1931.