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Telecommunication

""Telecom-icon.svg

"Telecommunications refers to wave-based communication technology through media such as air, cables etc. Telecommunication is the "transmission of "information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as "beacons, "smoke signals, "semaphore telegraphs, "signal flags, and optical "heliographs, or audio messages via coded drumbeats, lung-blown horns, or sent by loud whistles, for example. In the modern age of electricity and electronics, telecommunications now also includes the use of electrical devices such as "telegraphs, telephones, and "teleprinters, the use of radio and "microwave communications, as well as "fiber optics and their associated electronics, plus the use of "orbiting satellites and the Internet.

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""Waveguide17-with-UBR120-flanges.svg

In "electromagnetics and "communications engineering, the term "waveguide may refer to any linear structure that guides electromagnetic waves. However, the original and most common meaning is a hollow metal pipe used for this purpose.

A dielectric waveguide employs a solid "dielectric rod rather than a hollow pipe. An "optical fibre is a dielectric guide designed to work at optical frequencies. "Transmission lines such as "microstrip, "coplanar waveguide, "stripline or "coax may also be considered to be waveguides.

The electromagnetic waves in (metal-pipe) waveguide may be imagined as travelling down the guide in a zig-zag path, being repeatedly reflected between opposite walls of the guide. For the particular case of rectangular waveguide, it is possible to base an exact analysis on this view. Propagation in dielectric waveguide, may be viewed in the same way, with the waves confined to the dielectric by "total internal reflection at its surface.

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""Amateur Radio Station with multiple receivers and transceivers
Credit: "NX1Z

This "photograph shows the "receivers and "transceivers used in an "amateur radio station. Amateur radio is a hobby in which enthusiasts purchase or build their own equipment and use radio for their own enjoyment. Radio amateurs are licensed to use "frequencies in a large number of "narrow bands throughout the "radio spectrum.

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Telecommunications News from Wikinews


March 3, 2011: Telecom Commission of Solomon Islands issues phone company US$1M fine
February 22, 2011: Libya blocks access to Internet
September 1, 2010: Telstra becomes the first in the world to switch to HSPA+ wireless Internet technology

Selected biography

""Alexander Graham Bell.jpg

"Alexander Graham Bell ( March 3,1847 – August 2, 1922 ) was an outstanding "scientist, "inventor, and innovator. Born and brought up in "Scotland, he emigrated to "Canada, and later, the "United States. Over the years, his work and efforts were expressed between both countries. Bell is widely acclaimed as the prime developer of the "telephone, with considerable honourable mention to "Antonio Meucci and "Philipp Reis. In addition to Bell's work in "telecommunications, he was responsible for important advances in "aviation and "hydrofoil technology.

Did you know?

...that "Intelsat 1, known as Early Bird, launched in 1965, provided either 240 voice circuits or one two-way television channel between the United States and Europe.

...that the first telephone message was transmitted in 1876 from one room in "Alexander Graham Bell’s house to another.

...that in 1880 France rewarded Bell the "Volta Prize, worth 50,000 francs, for his invention.

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