History of telecommunication
[1][2] In Rabbinical Judaism a signal was given by means of kerchiefs or flags at intervals along the way back to the high priest to indicate the goat "for Azazel" had been pushed from the cliff.
Beacon chains suffered the drawback that they could only pass a single bit of information, so the meaning of the message such as "the enemy has been sighted" had to be agreed upon in advance.
The electrification of a wire by means of an electrostatic generator causes the corresponding elder ball to deflect and designate a letter to the operator located at the end of the line.
[6] French engineer Claude Chappe began working on visual telegraphy in 1790, using pairs of "clocks" whose hands pointed at different symbols.
[8] However, semaphore as a communication system suffered from the need for skilled operators and expensive towers often at intervals of only ten to thirty kilometers (six to nineteen miles).
An early experiment in electrical telegraphy was an 'electrochemical' telegraph created by the German physician, anatomist and inventor Samuel Thomas von Sömmerring in 1809, based on an earlier, less robust design of 1804 by Spanish polymath and scientist Francisco Salva Campillo.
Thus, messages could be conveyed electrically up to a few kilometers (in von Sömmerring's design), with each of the telegraph receiver's wires immersed in a separate glass tube of acid.
The telegraph receiver's operator would visually observe the bubbles and could then record the transmitted message, albeit at a very low baud rate.
[12] It used the deflection of needles to represent messages and started operating over twenty-one kilometres (thirteen miles) of the Great Western Railway on 9 April 1839.
Alfred Vail saw this demonstration and joined Morse to develop the register—a telegraph terminal that integrated a logging device for recording messages to paper tape.
[14] Transatlantic cables installed in 1857 and 1858 only operated for a few days or weeks (carried messages of greeting back and forth between James Buchanan and Queen Victoria) before they failed.
As with other great inventions such as radio, television, the light bulb, and the digital computer, there were several inventors who did pioneering experimental work on voice transmission over a wire, who then improved on each other's ideas.
[21] In 1880, Bell and co-inventor Charles Sumner Tainter conducted the world's first wireless telephone call via modulated lightbeams projected by photophones.
The first transatlantic telephone cable (which incorporated hundreds of electronic amplifiers) was not operational until 1956, only six years before the first commercial telecommunications satellite, Telstar, was launched into space.
[22] Over several years starting in 1894, the Italian inventor Guglielmo Marconi worked on adapting the newly discovered phenomenon of radio waves to telecommunication, building the first wireless telegraphy system using them.
[23] In December 1901, he established wireless communication between St. John's, Newfoundland and Poldhu, Cornwall (England), earning him a Nobel Prize in Physics (which he shared with Karl Braun) in 1909.
Millimetre wave communication was first investigated by Bengali physicist Jagadish Chandra Bose during 1894–1896, when he reached an extremely high frequency of up to 60 GHz in his experiments.
[32] On March 25, 1925, Scottish inventor John Logie Baird publicly demonstrated the transmission of moving silhouette pictures at the London department store Selfridge's.
[36] Zworykin's camera, based on Tihanyi's Radioskop, which later would be known as the Iconoscope, had the backing of the influential Radio Corporation of America (RCA).
In turn, this led to a significant increase in the total number of telephone subscribers, reaching nearly 1 billion users worldwide by the end of the 20th century.
There was a rapid growth of the telecommunications industry towards the end of the 20th century, primarily due to the introduction of digital signal processing in wireless communications, driven by the development of low-cost, very large-scale integration (VLSI) RF CMOS (radio-frequency complementary MOS) technology.
The concept of videotelephony was first popularized in the late 1870s in both the United States and Europe, although the basic sciences to permit its very earliest trials would take nearly a half century to be discovered.
This was first embodied in the device which came to be known as the video telephone, or videophone, and it evolved from intensive research and experimentation in several telecommunication fields, notably electrical telegraphy, telephony, radio, and television.
In 1960 NASA launched an Echo satellite; the 100-foot (30 m) aluminized PET film balloon served as a passive reflector for radio communications.
Belonging to AT&T as part of a multi-national agreement between AT&T, Bell Telephone Laboratories, NASA, the British General Post Office, and the French National PTT (Post Office) to develop satellite communications, it was launched by NASA from Cape Canaveral on July 10, 1962, the first privately sponsored space launch.
Realization and demonstration, on October 29, 2001, of the first digital cinema transmission by satellite in Europe[42][43][44] of a feature film by Bernard Pauchon,[45] Alain Lorentz, Raymond Melwig[46] and Philippe Binant.
[47] On September 11, 1940, George Stibitz was able to transmit problems using teletype to his Complex Number Calculator in New York City and receive the computed results back at Dartmouth College in New Hampshire.
However, it was not until the 1960s that researchers started to investigate packet switching a technology that would allow chunks of data to be sent to different computers without first passing through a centralized mainframe.
[55][56] The silicon-gate CMOS (complementary MOS) PCM codec-filter chip, developed by Hodges and W.C. Black in 1980,[55] has since been the industry standard for digital telephony.
[60][65] Most of the essential elements of modern wireless networks are built from MOSFETs, including base station modules, routers,[65] telecommunication circuits,[66] and radio transceivers.
