The Telecommunication Portal
Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information with an immediacy comparable to face-to-face communication. As such, slow communications technologies like postal mail and pneumatic tubes are excluded from the definition. Many transmission media have been used for telecommunications throughout history, from smoke signals, beacons, semaphore telegraphs, signal flags, and optical heliographs to wires and empty space made to carry electromagnetic signals. These paths of transmission may be divided into communication channels for multiplexing, allowing for a single medium to transmit several concurrent communication sessions. Several methods of long-distance communication before the modern era used sounds like coded drumbeats, the blowing of horns, and whistles. Long-distance technologies invented during the 20th and 21st centuries generally use electric power, and include the 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 -
Radar, Aircraft Interception, Mark IV (AI Mk. IV), also produced in the USA as SCR-540, was the world's first operational air-to-air radar system. Early Mk. III units appeared in July 1940 on converted Bristol Blenheim light bombers, while the definitive Mk. IV reached widespread availability on the Bristol Beaufighter heavy fighter by early 1941. On the Beaufighter, the Mk. IV arguably played a role in ending the Blitz, the Luftwaffe's night bombing campaign of late 1940 and early 1941.
Early development was prompted by a 1936 memo from Henry Tizard on the topic of night fighting. The memo was sent to Robert Watson-Watt, director of the radar research efforts, who agreed to allow physicist Edward George "Taffy" Bowen to form a team to study the problem of air interception. The team had a test bed system in flights later that year, but progress was delayed for four years by emergency relocations, three abandoned production designs and Bowen's increasingly adversarial relationship with Watt's replacement, Albert Rowe. Ultimately, Bowen was forced from the team just as the system was finally maturing. (Full article...)
General images
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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) -
"Doc" Herrold is shown at the microphone of KQW, early 1920s. (from History of broadcasting) -
Typical low-cost webcam used with many personal computers (from History of videotelephony) -
The Nipkow disk. This schematic shows the circular paths traced by the holes, which may also be square for greater precision. The area of the disk outlined in black shows the region scanned. (from History of television) -
British Post Office engineers inspect Guglielmo Marconi's wireless telegraphy (radio) equipment in 1897. (from History of radio) -
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) -
The master telephone patent granted to Bell, 174465, March 7, 1876 (from History of the telephone) -
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) -
The French Matra videophone (1970) (from History of videotelephony) -
AT&T Picturephone (Mod II) fully enclosed in its housing, control pad at bottom (courtesy: Richard Diehl) (from History of videotelephony) -
The British Broadcasting Corporation's landmark and iconic London headquarters, Broadcasting House, opened in 1932. At right is the 2005 eastern extension, the John Peel wing. (from History of broadcasting) -
Baird in 1925 with his televisor equipment and dummies "James" and "Stooky Bill" (right) (from History of television) -
Thomas Edison invented the carbon microphone which produced a strong telephone signal. (from History of the telephone) -
Ad for the beginning of experimental television broadcasting in New York City by RCA in 1939 (from History of television) -
Top of cellular telephone tower (from History of the telephone) -
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Oliver Lodge's 1894 lectures on Hertz demonstrated how to transmit and detect radio waves. (from History of radio) -
Heinrich Rudolf Hertz (1856–1894) proved the existence of electromagnetic radiation. (from History of radio) -
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The 1969 AT&T Mod II Picturephone, the result of decades long R&D at a cost of over $500M. (from History of telecommunication)
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Code of letters and symbols for Chappe telegraph (Rees's Cyclopaedia) (from History of telecommunication) -
A replica of one of Claude Chappe's semaphore towers (optical telegraph) in Nalbach, Germany (from History of telecommunication) -
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) -
Early experiment demonstrating refraction of microwaves by a paraffin lens by John Ambrose Fleming in 1897 (from History of radio) -
Elisha Gray, 1876, designed a telephone using a water microphone in Highland Park, Illinois. (from History of the telephone) -
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The first mass-produced Czechoslovak TV-set Tesla 4001A (1953–57) (from History of television) -
Guglielmo Marconi (from History of broadcasting) -
The Philco Predicta, 1958. In the collection of The Children's Museum of Indianapolis (from History of television) -
Right side view, housing removed, one of its printed circuit boards exposed (courtesy: Richard Diehl) (from History of videotelephony) -
Reginald Fessenden (around 1906) (from History of radio) -
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DBS satellite dishes (from History of television) -
Bell prototype telephone stamp(from History of the telephone)
Centennial Issue of 1976 -
Alexander Graham Bell was awarded the first U.S. patent for the invention of the telephone in 1876. (from History of the telephone) -
The Australian Broadcasting Corporation logo, first introduced in 1975 and based on the Lissajous curve (from History of broadcasting) -
Antonio Meucci's telephone. (from History of the telephone) -
Philo Farnsworth in 1924 (from History of television) -
Artist's conception: 21st-century videotelephony imagined in the early 20th century (1910) (from History of videotelephony) -
Color bars used in a test pattern, sometimes used when no program material is available (from History of television) -
Swedish Prime Minister Tage Erlander using an Ericsson videophone to speak with Lennart Hyland, a popular TV show host (1969) (from History of videotelephony) -
Australian radio sets usually had the positions of radio stations marked on their dials. The illustration is a dial from a transistorised, mains-operated Calstan radio, circa 1960s. (Click image for a high resolution view, with readable callsigns.) (from History of broadcasting) -
1917 wall telephone, open to show magneto and local battery (from History of the telephone) -
Reginald Fessenden, the "father" of radio broadcasting in the US (from History of broadcasting) -
Historical marker commemorating the first telephone central office in New York State (1878) (from History of the telephone) -
Family watching TV, 1958 (from History of television) -
Donald Manson working as an employee of the Marconi Company (England, 1906) (from History of radio)
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AT&T magazine advertisement announcing commercial launch of Picturephone service. (from History of videotelephony) -
First television test broadcast transmitted by the NHK Broadcasting Technology Research Institute in May 1939 (from History of television) -
Caricature of Sir John Reith, by Wooding (from History of broadcasting) -
Early pioneers of radio science and technology in the United States including Charles Steinmetz, David Sarnoff, Irving Langmuir and Alfred Goldsmith in 1921, photographed next to the antenna feed wires of the New Brunswick Marconi Station, one of the first transatlantic radio links. Photo includes Albert Einstein as a visiting guest. (from History of radio) -
An exposed view of the Picturephone's rear circuit board (courtesy: Richard Diehl) (from History of videotelephony) -
Receiver schematic, c.1906 (from History of the telephone) -
Reis's telephone around 1861, first device called telephone (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) -
An early Smart TV from 2012 running the discontinued Orsay platform (from History of television) -
Antonio Meucci, 1854, constructed telephone-like devices. (from History of the telephone) -
The Regency TR-1, which used Texas Instruments' NPN transistors, was the world's first commercially produced transistor radio in 1954. Size: 3×5×1.25 inch (7.6×12.7×3.2 cm) (from History of radio) -
A French Gower telephone of 1912 at the Musée des Arts et Métiers in Paris (from History of the telephone) -
Private conversation, 1910 (from History of the telephone) -
The master telephone patent, 174465, granted to Bell, March 7, 1876 (from History of telecommunication)
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Apple iPhone smartphone (from History of the telephone) -
Lee DeForest broadcasting Columbia phonograph records on pioneering New York station 2XG, in 1916 (from History of broadcasting) -
Broadcasting pioneer Frank Conrad in a 1921 portrait (from History of broadcasting) -
The "Kerbango Internet Radio" was the first stand-alone product that let users listen to Internet radio without a computer. (from History of broadcasting) -
Charles Logwood broadcasting at station 2XG, New York City, circa November, 1916 (from History of broadcasting) -
Naomi ("Joan") Melwit and Norman Banks at the 3KZ microphone, in the late 1930s (from History of broadcasting) -
A 19th century acoustic tin can or "lovers' telephone" (from History of the telephone) -
Philipp Reis, 1861, constructed the first telephone, today called the Reis telephone. (from History of the telephone) -
Manfred von Ardenne in 1933 (from History of television) -
Emil Voigt, founder of 2KY on behalf of the Labor Council of New South Wales. This photo was taken in earlier days when Voight was a prominent British athlete, and winner of the Gold Medal for the five mile race at the 1908 Summer Olympics in London. (from History of broadcasting) -
1896 telephone (Sweden) (from History of the telephone) -
RCA 630-TS, the first mass-produced television set, which sold in 1946–1947 (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 a build an effective crystal radio receiver. (from History of radio) -
"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)
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Selected biography -
Ronald Hugh Barker FIEE (28 October 1915 – 7 October 2015) was an Irish physicist and pioneer in his field of digital technology. Inventor of Barker code a method for synchronising digital communication to avoid corruption of the data received.
Barker's ground breaking contributions to digital technology have had a lasting influence on the design of digital communication systems and error-correcting codes. Barker codes continue to play a vital role in modern signal processing and communication technologies, demonstrating the enduring relevance of this mid-20th-century discovery in today’s highly interconnected world. The method has been studied and researched worldwide and is commonly used in most data transmissions today. His invention continues to be a fundamental tool in various modern technologies. Examples of applications include radar, mobile phone technology, telemetry, digital speech, ultrasound imaging and testing, GPS, Wi-Fi, radio frequency identification, barcodes, tracking, stock control and vehicle guidance. (Full article...)
Did you know (auto-generated) -
- ... that a Florida radio station DJ's attempt to break a world record was foiled by blown transmitter tubes?
- ... that a Washington state radio station turned to "professional bikini watchers"—military recruiters—to report on crowds at local beaches?
- ... that a Hawaii radio station couldn't buy a KISS?
- ... that after his movement's victory in the Cuban Revolution, television broadcasts showed Camilo Cienfuegos freeing parrots from birdcages, declaring that the birds had "a right to liberty"?
- ... that Daniel Chapo, the favorite to be the next president of Mozambique, was previously a radio announcer?
- ... that an episode of the children's TV show Arthur featuring a same-sex wedding was not aired on Alabama's PBS network?
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