| Abstract from DBPedia | Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that feasible with the human voice, but with a similar scale of expediency; thus, slow systems (such as postal mail) are excluded from the field. The transmission media in telecommunication have evolved through numerous stages of technology, from beacons and other visual signals (such as smoke signals, semaphore telegraphs, signal flags, and optical heliographs), to electrical cable and electromagnetic radiation, including light. Such transmission paths are often divided into communication channels, which afford the advantages of multiplexing multiple concurrent communication sessions. Telecommunication is often used in its plural form. Other examples of pre-modern long-distance communication included audio messages, such as coded drumbeats, lung-blown horns, and loud whistles. 20th- and 21st-century technologies for long-distance communication usually involve electrical and electromagnetic technologies, such as telegraph, telephone, television and teleprinter, networks, radio, microwave transmission, optical fiber, and communications satellites. A revolution in wireless communication began in the first decade of the 20th century with the pioneering developments in radio communications by Guglielmo Marconi, who won the Nobel Prize in Physics in 1909, and other notable pioneering inventors and developers in the field of electrical and electronic telecommunications. These included Charles Wheatstone and Samuel Morse (inventors of the telegraph), Antonio Meucci and Alexander Graham Bell (some of the inventors and developers of the telephone, see Invention of the telephone), Edwin Armstrong and Lee de Forest (inventors of radio), as well as Vladimir K. Zworykin, John Logie Baird and Philo Farnsworth (some of the inventors of television). According to Article 1.3 of the Radio Regulations (RR), telecommunication is defined 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.» This definition is identical to those contained in the Annex to the Constitution and Convention of the International Telecommunication Union (Geneva, 1992). The early telecommunication networks were created with copper wires as the physical medium for signal transmission. For many years, these networks were used for basic phone services, namely voice and telegrams. Since the mid-1990s, as the internet has grown in popularity, voice has been gradually supplanted by data. This soon demonstrated the limitations of copper in data transmission, prompting the development of optics.電気通信（でんきつうしん）とは、電気信号や電磁波（電波・赤外線・可視光線）等の電磁的手段により映像・音声・データなどの情報を伝える通信である。 電気通信分野の初期の発明者としては、アレクサンダー・グラハム・ベル、グリエルモ・マルコーニ、ジョン・ロジー・ベアードらが挙げられる。 電気通信は世界経済の重要な部分となっており、2006年の全世界の電気通信業界の収入は1兆2千億ドルと見積もられている。 有線通信・無線通信という区分があるが、現在の通信ネットワークは有線・無線を適材適所に組み合わせて構築される。 (Source: http://dbpedia.org/resource/Telecommunications) |
