Jump to content


From Wikipedia, the free encyclopedia

The Telecommunication Portal

Earth station at the satellite communication facility Raisting Earth Station in Raisting, Bavaria, Germany

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 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...)

Animation of audio, AM and FM signals
A signal may be carried by an AM or FM radio wave.

Frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. The technology is used in telecommunications, radio broadcasting, signal processing, and computing.

In analog frequency modulation, such as radio broadcasting, of an audio signal representing voice or music, the instantaneous frequency deviation, i.e. the difference between the frequency of the carrier and its center frequency, has a functional relation to the modulating signal amplitude. (Full article...)
List of selected articles

General images

The following are images from various telecommunication-related articles on Wikipedia.

Things to do

Here are some tasks awaiting attention:

Selected biography - show another

Nipkow c. 1884

Paul Julius Gottlieb Nipkow (22 August 1860 – 24 August 1940) was a German technician and inventor. He invented the Nipkow disk, which laid the foundation of television, since his disk was a fundamental component in the first televisions. Hundreds of stations experimented with television broadcasting using his disk in the 1920s and 1930s, until it was superseded by all-electronic systems in the 1940s.

Nipkow has been called the "father of television", together with other early figures of television history like Karl Ferdinand Braun. (Full article...)

Did you know (auto-generated) - load new batch



Category puzzle
Category puzzle
Select [►] to view subcategories

Associated Wikimedia

The following Wikimedia Foundation sister projects provide more on this subject:

Discover Wikipedia using portals

Purge server cache