August 6, 2003

History of telecommunications

Since time immemorial, people have needed to communicate over long distances.

Early attempts at long-distance communications include torches and light beacons in Ancient Greece, drums and bugles on battlefields, tom-toms in the savannah, smoke signals used by Native Americans, horns at fortified castles and yodelling in the Alps.

However, light and sound signals can only carry a few miles. The first real communications network appeared at the end of the French Revolution. The visual telegraph, developed by Claude Chappe, linked Paris and Lille by a series of towers along which coded messages were sent using semaphore.

Half a century later, it was superseded by the electric telegraph. This transmitted signals using metal wires, meaning it could also be used at night and in adverse atmospheric conditions. The system was later improved by the introduction of Morse code.

The electric telegraph also prompted early research into the transmission of still images. Line-by-line analysis and transmission of photographs was extended to moving pictures, culminating in television, which appeared around 1920. Underwater cables made it possible to progressively establish links between continents.
The telephone also appeared around this time. Based on the concept of electromagnetism, it converts the sound vibrations of the human voice into electrical signals using a magnetic field. 
Did you know?
Keeping track...
In France, telegraphs and trains ran side by side, as the country's telegraph network was set up in partnership with the rail companies. The telegraph lines ran alongside the railway tracks, so they could be monitored at all times. Railway workers also used them to send messages between stations.
Antiquity First messages transmitted using optical and acoustic systems in Greece, Egypt, Rome, Gaul and China
1792 French engineer Claude Chappe unveils the visual telegraph
12 July 1793 First transmission between Belleville and Saint-Martin-du-Tertre (near Paris), a distance of 35 kilometres
August 1794 Opening of the visual telegraph line between Paris and Lille
1837 Advent of the electric telegraph
24 May 1844 First transmission of an electric telegram using a printing telegraph and Morse code
1846 Opening of France's first operational electric telegraph line, between Paris and Lille.
1851 First underwater electric cable laid between England and France
18 August 1858 First transatlantic telegraph message
1868 Transmission of uncoded messages using the electric telegraph
June 1876 First telephone conversation
1877 First urban telephone networks established in New York
1901 Wireless link between Cornwall and Newfoundland, a distance of 3,400 kilometres
1904 First transmission of a photograph, between Munich and Nuremberg
1908 Radiotelephone link between Brittany and Paris
1923 Advent of television, based on the same principles used today
10 November 1935 Official launch of television broadcasting in France
1940 First operational use of analogue cordless telephones, in the United States
1946 Telex introduced in France
10 July 1962 Launch of Telstar, the first telecommunications satellite, in the United States
1977 First commercial fibre-optic telephone link, in the United States
10 July 1981 Launch of Minitel, France's viewdata service
1982 Official adoption of standard Internet protocols
1992 Market launch of second-generation mobile telephones, which use the GSM digital network

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