Portal:Telecommunication
The Telecommunication Portal
Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electrical or electronic means, typically through cables, radio waves, or other communication technologies. These means of transmission may be divided into communication channels for multiplexing, allowing for a single medium to transmit several concurrent communication sessions. Long-distance technologies invented during the 19th, 20th and 21st centuries generally use electric power, and include the electrical telegraph, telephone, television, and radio.
Early telecommunication networks used metal wires as the medium for transmitting signals. These networks were used for telegraphy and telephony for many decades. In the first decade of the 20th century, a revolution in wireless communication began with breakthroughs including those made in radio communications by Guglielmo Marconi, who won the 1909 Nobel Prize in Physics. Other early pioneers in electrical and electronic telecommunications include co-inventors of the telegraph Charles Wheatstone and Samuel Morse, numerous inventors and developers of the telephone including Antonio Meucci, Philipp Reis, Elisha Gray and Alexander Graham Bell, inventors of radio Edwin Armstrong and Lee de Forest, as well as inventors of television like Vladimir K. Zworykin, John Logie Baird and Philo Farnsworth.
Since the 1960s, the proliferation of digital technologies has meant that voice communications have gradually been supplemented by data. The physical limitations of metallic media prompted the development of optical fibre. The Internet, a technology independent of any given medium, has provided global access to services for individual users and further reduced location and time limitations on communications. (Full article...)
Selected article -
Morse code is a telecommunications method which encodes text characters as standardized sequences of two different signal durations, called dots and dashes, or dits and dahs. It is named after Samuel Morse, one of several developers of the system. Morse's preliminary proposal for a telegraph code was replaced by an alphabet-based code developed by Alfred Vail, the engineer working with Morse. Vail's version was used for commercial telegraphy in North America. Friedrich Gerke simplified Vail's code to produce the code adopted in Europe, and most of the alphabetic part of the (ITU) "Morse" is copied from Gerke's revision.
The ITU International Morse code encodes the 26 basic Latin letters A to Z, one accented Latin letter É, the Indo-Arabic numerals 0 to 9, and some punctuation and messaging procedural signals (prosigns). There is no distinction between upper and lower case letters. Each code symbol is formed by a sequence of dits and dahs. The dit duration can vary for signal clarity and operator skill, but for any one message, once the rhythm is established, a half-beat is the basic unit of time measurement. The duration of a dah is three times the duration of a dit. Each dit or dah within an encoded character is followed by a period of signal absence, called a space, equal to the dit duration. The letters of a word are separated by a space of duration equal to three dits, and words are separated by a space equal to seven dits. (Full article...)
General images
Replica of the telettrofono at Museo Nazionale Scienza e Tecnologia Leonardo da Vinci of Milan, Italy, invented by Antonio Meucci and credited by several sources as the first telephone. (from History of the telephone)
John Logie Baird in 1925 with his televisor equipment and dummies "James" and "Stooky Bill" (right) (from History of television)
The Philco Predicta, 1958. In the collection of The Children's Museum of Indianapolis (from History of television)
The first commercial AM Audion vacuum tube radio transmitter, built in 1914 by Lee De Forest who invented the Audion (triode) in 1906 (from History of radio)
Typical low-cost webcam used with many personal computers (from History of videotelephony)
AT&T Picturephone (Mod II) fully enclosed in its housing, control pad at bottom (from History of videotelephony)
The earliest photograph of a television picture, showing the face of Oliver Hutchinson in June 1926. The television picture was projected using Baird's television camera. (from History of television)
Tihanyi' Radioskop patent (1926) was recognized as Document of Universal Significance by the UNESCO (from History of television)
The Kyocera VP-210 Visual Phone was the first commercial mobile videophone. The Personal Handy-phone System (PHS) phone was introduced in Japan (1999). (from History of videotelephony)
Ad for the beginning of experimental television broadcasting in New York City by RCA in 1939 (from History of television)
In the 1920s, the United States government publication, "Construction and Operation of a Simple Homemade Radio Receiving Outfit", showed how almost any person handy with simple tools could build an effective crystal radio receiver. (from History of radio)
An early Smart TV from 2012 running the discontinued Orsay platform (from History of television)
Manfred von Ardenne in 1933 (from History of television)
Around 1920, radio broadcasting started to get popular. The Brox Sisters, a popular singing group, gathered around the radio at the time. (from History of radio)
"Doc" Herrold is shown at the microphone of KQW, c. 1925 (from History of broadcasting)
Thomas Edison invented the carbon microphone which produced a strong telephone signal. (from History of the telephone)
Code of letters and symbols for Chappe telegraph (Rees's Cyclopaedia) (from History of telecommunication)
An early experiment demonstrating the refraction of microwaves by a paraffin lens by John Ambrose Fleming in 1897 (from History of radio)
Receiver schematic, c.1906 (from History of the telephone)
Guglielmo Marconi (from History of broadcasting)
Artist's conception: 21st-century videotelephony imagined in the early 20th century (1910) (from History of videotelephony)
The "Kerbango Internet Radio" was the first stand-alone product that let users listen to Internet radio without a computer. (from History of broadcasting)
Private conversation, 1910 (from History of the telephone)
Fessenden operating an underwater oscillator in 1915. (from History of radio)
Portrait of John Reith, 1st Baron Reith, in 1925, founding director general of the BBC from 1922 to 1938 (from History of broadcasting)
A French Gower telephone of 1912 at the Musée des Arts et Métiers in Paris (from History of the telephone)
Charles Logwood broadcasting at New York station 2XG, 1916 (from History of broadcasting)
Heinrich Rudolf Hertz (1856–1894) proved the existence of electromagnetic radiation. (from History of radio)
Bell prototype telephone stamp(from History of the telephone)
Centennial Issue of 1976
Family watching TV, 1958 (from History of television)
The first mass-produced Czechoslovak TV-set Tesla 4001A (1953–57) (from History of television)
Apple iPhone smartphone (from History of the telephone)- The 1969 AT&T Mod II Picturephone, the result of decades long R&D at a cost of over $500M. (from History of telecommunication)
The French Matra videophone (1970) (from History of videotelephony)
"Fiction becomes fact": Imaginary "Edison" combination videophone-television, conceptualized by George du Maurier and published in Punch magazine. The drawing also depicts then-contemporary speaking tubes, used by the parents in the foreground and their daughter on the viewing display (1878). (from History of videotelephony)
Reginald Fessenden, the "father" of radio broadcasting in the U.S. (from History of broadcasting)
The Marconi Company was formed in England in 1910. The photo shows a typical early scene, from 1906, with Marconi employee Donald Manson at right. (from History of broadcasting)
Swedish Prime Minister Tage Erlander using an Ericsson videophone to speak with Lennart Hyland, a popular TV show host (1969) (from History of videotelephony)
The master telephone patent granted to Bell, 174465, March 7, 1876 (from History of the telephone)
Antonio Meucci, 1849, developing a voice-communication apparatus that several sources credit as the first telephone. (from History of the telephone)
1896 telephone (Sweden) (from History of the telephone)
Actor portraying Alexander Graham Bell in a 1932 silent film. Shows Bell's second telephone transmitter (microphone), invented 1876 and first displayed at the Centennial Exposition, Philadelphia. (from History of the telephone)
Broadcasting pioneer Frank Conrad in a 1921 portrait (from History of broadcasting)
Naomi ("Joan") Melwit and Norman Banks at the 3KZ microphone, in the late 1930s (from History of broadcasting)
Reis's telephone around 1861, first device called telephone (from History of the telephone)
Innocenzo Manzetti considered the idea of a telephone in 1844 (from History of the telephone)
Philipp Reis, 1861, constructed the first telephone, today called the Reis telephone. (from History of the telephone)
Historical marker commemorating the first telephone central office in New York State (1878) (from History of the telephone)
1917 wall telephone, open to show magneto and local battery (from History of the telephone)
.jpg)
_LCCN2014717186.jpg)
.jpg)
_%E2%80%93_National_Portrait_Gallery,_London.jpg)
._Photograph_by_L._Alman._Wellcome_V0026857.jpg)
.jpg)
Things to do
 |
Here are some tasks awaiting attention:
|
Selected biography -
Nikola Tesla (10 July 1856 – 7 January 1943) was a Serbian-American engineer, futurist, and inventor. He is known for his contributions to the design of the modern alternating current (AC) electricity supply system.
Born and raised in the Austro-Hungarian Empire, Tesla first studied engineering and physics in the 1870s without receiving a degree. He then gained practical experience in the early 1880s working in telephony and at Continental Edison in the new electric power industry. In 1884, he migrated to the United States, where he became a naturalized citizen. He worked for a short time at the Edison Machine Works in New York City before he struck out on his own. With the help of partners to finance and market his ideas, Tesla set up laboratories and companies in New York to develop a range of electrical and mechanical devices. His AC induction motor and related polyphase AC patents, licensed by Westinghouse Electric in 1888, earned him a considerable amount of money and became the cornerstone of the polyphase system, which Westinghouse marketed. (Full article...)
Did you know (auto-generated) -
- ... that a Connecticut radio station left the FM band for good after it was out of service for a week and only one person wrote a letter to complain?
- ... that television producer Paul Graham insisted on "a big game feel" for the sportscast he considered his "baby"?
- ... that Indonesian radio presenters Muhammad Farhan and Indy Barends co-hosted a 32-hour nonstop radio show in 2001, setting a national record which they held until 2019?
- ... that Luis Estrada declined to produce The Dead Girls as an English-language film before directing it as a Spanish-language television series?
- ... that, although Self's fifth studio album was cancelled, its songs were still used in television commercials?
- ... that a public service announcement about drunk driving was voted the best television advertisement in New Zealand?
Related portals
Topics
{ }}
Subcategories
Associated Wikimedia
The following Wikimedia Foundation sister projects provide more on this subject:
-
Commons
Free media repository -
Wikibooks
Free textbooks and manuals -
Wikidata
Free knowledge base -
Wikiquote
Collection of quotations -
Wikisource
Free-content library -
Wikiversity
Free learning tools -
Wiktionary
Dictionary and thesaurus
