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.
Cambridge (/ˈkeɪmbrɪdʒ/ KAYM-brij) is a university city and the county town of Cambridgeshire, England, on the River Cam approximately 55 miles (89 km) north of London. At the United Kingdom Census 2011, the population of the Cambridge built-up area (which is larger than the remit of Cambridge City Council) was 158,434 including 29,327 students. Cambridge became an important trading centre during the Roman and Viking ages, and there is archaeological evidence of settlement in the area as early as the Bronze Age. The first town charters were granted in the 12th century, although modern city status was not officially conferred until 1951.
The University of Cambridge was founded in 1209. The buildings of the university include King's College Chapel, Cavendish Laboratory, and the Cambridge University Library, one of the largest legal deposit libraries in the world. The city's skyline is dominated by several college buildings, along with the spire of the Our Lady and the English Martyrs Church, and the chimney of Addenbrooke's Hospital. Anglia Ruskin University, which evolved from the Cambridge School of Art and the Cambridgeshire College of Arts and Technology, also has its main campus in the city.
Cambridge is at the heart of the high-technology Silicon Fen with industries such as software and bioscience and many start-up companies born out of the university. Over 40 per cent of the workforce have a higher education qualification, more than twice the national average. The Cambridge Biomedical Campus, one of the largest biomedical research clusters in the world, is soon to house premises of AstraZeneca, a hotel, and the relocated Royal Papworth Hospital.
The first game of association football took place at Parker's Piece. The Strawberry Fair music and arts festival and Midsummer Fair are held on Midsummer Common, and the annual Cambridge Beer Festival takes place on Jesus Green. The city is adjacent to the M11 and A14 roads. Cambridge station is less than an hour from London King's Cross railway station.