Telecommunications

Telecommunication, often shortened to telecom, is the practice of sending information across distances by electrical or electronic methods, usually via cables, radio waves, or similar technologies. These transmission paths can be split into separate channels through multiplexing, letting a single medium carry multiple conversations at once. Long-distance systems developed in the 1800s, 1900s, and 2000s generally rely on electric power, and include the telegraph, telephone, television, and radio.

Early telecom networks used metal wires to carry signals, serving telegraphy and telephony for many decades. In the early 1900s, wireless communication took off with breakthroughs like those by Guglielmo Marconi, who received the 1909 Nobel Prize in Physics for his radio work. Other key figures in early electrical and electronic telecom include telegraph co-inventors Charles Wheatstone and Samuel Morse; telephone developers Antonio Meucci, Philipp Reis, Elisha Gray, and Alexander Graham Bell; radio inventors Edwin Armstrong and Lee de Forest; and television pioneers Vladimir K. Zworykin, John Logie Baird, and Philo Farnsworth.

From the 1960s onward, the spread of digital technology gradually added data to voice communications. The limits of metal wires led to the development of optical fiber. The Internet, which works independently of any specific medium, has given individuals worldwide access to services and further reduced the constraints of location and time.

**Definition**

In 1932, at the Plenipotentiary Telegraph Conference and International Radiotelegraph Conference in Madrid, two organizations merged to create the International Telecommunication Union (ITU). They defined telecommunication as "any telegraphic or telephonic communication of signs, signals, writing, facsimiles and sounds of any kind, by wire, wireless or other systems or processes of electric signaling or visual signaling (semaphores)." This definition was later reaffirmed in Article 1.3 of the ITU Radio Regulations, which described it as "Any transmission, emission or reception of signs, signals, writings, images and sounds or intelligence of any nature by wire, radio, optical, or other electromagnetic systems." As a result, slower methods like postal mail and pneumatic tubes are not considered telecommunication. The term itself was coined in 1904 by French engineer and novelist Édouard Estaunié, who called it "remote transmission of thought through electricity." The word is a compound of the Greek prefix *tele-* (τῆλε), meaning far off, and the Latin verb *communicare*, meaning to share. *Communication* entered English in the late 1300s, from Old French and Latin roots meaning to make common.

**History**

Throughout history, many transmission media have been used for long-distance communication, from smoke signals, beacons, semaphore telegraphs, signal flags, and optical heliographs to wires and empty space carrying electromagnetic signals.

**Before the electrical and electronic era**

Long-distance communication existed long before electricity and electromagnetism enabled telecom. Homing pigeons were used by various cultures, with pigeon post originating in ancient Persia and later employed by the Roman military. Frontinus claimed Julius Caesar used pigeons as messengers in Gaul. Greeks sent Olympic victors' names to cities via pigeons. In the early 1800s, the Dutch government used the system in Java and Sumatra. In 1849, Paul Julius Reuter started a pigeon service to fly stock prices between Aachen and Brussels, which ran for a year until a telegraph link filled the gap. In the Middle Ages, hilltop beacon chains relayed signals, but they could only pass a single bit of information—like "the enemy has been sighted"—which had to be agreed upon in advance. A notable use was during the Spanish Armada, when a beacon chain sent a signal from Plymouth to London. In 1792, French engineer Claude Chappe built the first fixed visual telegraphy system (a semaphore line) between Lille and Paris. However, semaphore needed skilled operators and expensive towers every ten to thirty kilometers, and the last commercial line closed in 1880 due to competition from the electrical telegraph.

**Telegraph and telephone**

On July 25, 1837, English inventor Sir William Fothergill Cooke and scientist Sir Charles Wheatstone demonstrated the first commercial electrical telegraph. They considered it an improvement to the existing electromagnetic telegraph, not a new device. Samuel Morse independently developed his own version, which he unsuccessfully demonstrated on September 2, 1837. His code was a major advance over Wheatstone's signaling method. The first transatlantic telegraph cable was successfully completed.