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Teletext Viewdata Terminal
Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipped television sets. Teletext sends data in the broadcast signal, hidden in the invisible vertical blanking interval area at the top and bottom of the screen. The teletext decoder in the television buffers this information as a series of "pages", each given a number. The user can display chosen pages using their remote control. In broad terms, it can be considered as Videotex, a system for the delivery of information to a user in a computer-like format, typically displayed on a television or a dumb terminal, but that designation is usually reserved for systems that provide bi-directional communication, such as Prestel or Minitel. Teletext was created in the United Kingdom in the early 1970s by John Adams, Philips' lead designer for video display units to provide closed captioning to television shows for the hearing impaired. Public teletext information services were in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiope (teletext)
Antiope was a French teletext standard in the 1980s. It also formed the basis for the display standard used in the French videotex service Minitel. The term allegedly stood for ''Acquisition Numérique et Télévisualisation d’Images Organisées en Pages d’Écriture'', which could be loosely translated as ''Digital Acquisition and Remote Visualization of Images Organized into Written Pages''. History Work on Antiope started in 1972 at CCETT, the newly merged French national research centre for television and telecommunications in Rennes, with first field trials in 1975. The system was officially launched in 1976 at Vidcom in Cannes, and simultaneously at the СПОРТ 76 exposition in Moscow. It was adopted into the international standard CCIR 653 (now ITU-R BT.653) of 1986 as CCIR Teletext System A. Commercial broadcasting of Antiope began on Antenne 2 in 1979. To publicise the service, pages were even transmitted ''en clair'' instead of the test card (compare the BBC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Independent Television Authority
The Independent Television Authority (ITA) was an agency created by the Television Act 1954 ( 2 & 3 Eliz. 2. c. 55) to supervise the creation of " Independent Television" (ITV), the first commercial television network in the United Kingdom. The ITA existed from 1954 until 1972. It was responsible for determining the location, constructing, building, and operating the transmission stations used by the ITV network, as well as determining the franchise areas and awarding the franchises for each regional commercial broadcaster. The authority began its operations on 4 August 1954, a mere four days after the Television Act 1954 received royal assent, under the chairmanship of Sir Kenneth Clark. The authority's first director general, Sir Robert Fraser was appointed by Clark a month later on 14 September. The physics of VHF broadcasting meant that a comparatively small number of transmitters could cover the majority of the population of Britain, if not the bulk of the area of the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viewdata
Viewdata is a Videotex implementation. It is a type of information retrieval service in which a subscriber can access a remote database via a common carrier channel, request data and receive requested data on a video display over a separate channel. Samuel Fedida, who had the idea for Viewdata in 1968, was credited as inventor of the system which was developed while working for the British Post Office which was the operator of the national telephone system. The first prototype became operational in 1974. The access, request and reception are usually via common carrier broadcast channels. This is in contrast with teletext. Design Viewdata offered a display of 40×24 characters, based on ISO 646 (IRV IA5) – 7 bits with no accented characters. Originally, Viewdata was accessed with a special purpose terminal (or emulation software) and a modem running at ITU-T V.23 speed (1,200 bit/s down, 75 bit/s up). By 2004, it was normally accessed over TCP/IP using Viewdata clien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Telecom
BT Group plc (formerly British Telecom) is a British Multinational corporation, multinational telecommunications holding company headquartered in London, England. It has operations in around 180 countries and is the largest provider of fixed-line, Internet access, broadband and Mobile telephony, mobile services in the UK, and also provides subscription television and Information technology, IT services. BT's origins date back to the founding in 1846 of the Electric Telegraph Company, the world's first public telegraph company, which developed a nationwide communications network. BT Group as it came to be started in 1912, when the General Post Office, a government department, took over the system of the National Telephone Company becoming the monopoly telecoms supplier in the United Kingdom. The Post Office Act of 1969 led to the GPO becoming a public corporation, Post Office Telecommunications. The ''British Telecom'' brand was introduced in 1980, and became independent of the R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bandwidth (computing)
In computing, bandwidth is the maximum rate of data transfer across a given path. Bandwidth may be characterized as network bandwidth, data bandwidth, or digital bandwidth. This definition of ''bandwidth'' is in contrast to the field of signal processing, wireless communications, modem data transmission, digital communications, and electronics, in which ''bandwidth'' is used to refer to the signal bandwidth measured in hertz, meaning the frequency range between lowest and highest attainable frequency while meeting a well-defined impairment level in signal power. The actual bit rate that can be achieved depends not only on the signal bandwidth but also on the noise on the channel. Network capacity The term ''bandwidth'' sometimes defines the net bit rate ''peak bit rate'', ''information rate'', or physical layer ''useful bit rate'', channel capacity, or the maximum throughput of a logical or physical communication path in a digital communication system. For example, bandwi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceefax Test Screenshot 1972
Ceefax () was the world's first teletext information service and a forerunner to the current BBC Red Button service. Ceefax was started by the BBC in 1974 and ended, after 38 years of broadcasting, at 23:32:19 BST (11:32 PM BST) on 23 October 2012, in line with the digital switchover completion in Northern Ireland. Pete Clifton Points of View 9 November 2008Test Cards and Ceefax BBC Archive To receive a desired page of text on a teletext-capable receiver, the user entered a three-digit page number on the device. The selected page was displayed on the user's screen as it was transmitted, requiring a wait of several seconds. There were many pages to choose from, and they could be displayed either on a black background or superimposed over the broadcast programme picture. This latter feature m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multimedia Home Platform
Multimedia Home Platform (DVB-MHP) is an open middleware system standard designed by the DVB project for interactive digital television. The MHP enables the reception and execution of interactive, Java-based applications on a TV set. Interactive TV applications can be delivered over the broadcast channel, together with audio and video streams. These applications can be for example information services, games, interactive voting, e-mail, SMS or shopping. MHP applications can use an additional return channel that has to support IP. Deployment In May 2010 the largest deployments DVB-MHP are in Italy (DVB-T), Korea ( DVB-S), Belgium ( DVB-C) and Poland ( DVB-S) with trials or small deployments in Germany, Spain, Austria, Colombia, Uruguay and Australia. MHP service was also offered in Finland by Finnish Broadcasting Corporation ( Yleisradio), but the service was shut down at the end of 2007 after technical failure. The shutdown wasn't ever officially announced. Ultimately the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MHEG-5
MHEG-5, or ISO/ IEC 13522–5, is part of a set of international standards relating to the presentation of multimedia information, standardised by the Multimedia and Hypermedia Experts Group (MHEG). It is most commonly used as a language to describe interactive television services. Characteristics MHEG-5 is a licence-free and public standard for interactive TV middleware that is used both to send and receive interactive TV signals. It allows a wide range of TV-centric interactive services to be deployed. It is used by Freeview and Freesat in the UK, Freeview in New Zealand, TVB in Hong Kong, Freeview in Australia, Saorview in Ireland and has been specified in South Africa. Recent work by the DTG in the UK has led to the development of the MHEG-5 Interaction Channel (MHEG-IC), which enables an extension of broadcast interactive services to be delivered via an IP connection. The principles behind the MHEG-IC are to provide a seamless viewer experience of broadcast delivered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Television
Digital television (DTV) is the transmission of television signals using Digital signal, digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an innovative advancement and represented the first significant evolution in television technology since color television in the 1950s. Modern digital television is transmitted in high-definition television (HDTV) with greater resolution than analog TV. It typically uses a widescreen aspect ratio (commonly 16:9) in contrast to the narrower format (4:3) of analog TV. It makes more economical use of scarce radio spectrum space; it can transmit up to seven channels in the same Bandwidth (signal processing), bandwidth as a single analog channel, and provides many new features that analog television cannot. A digital television transition, transition from analog to digital broadcasting began around 2000. Different digital television broadcasting st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet
The Internet (or internet) is the Global network, global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a internetworking, network of networks that consists of Private network, private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, Wireless network, wireless, and optical networking technologies. The Internet carries a vast range of information resources and services, such as the interlinked hypertext documents and Web application, applications of the World Wide Web (WWW), email, electronic mail, internet telephony, streaming media and file sharing. The origins of the Internet date back to research that enabled the time-sharing of computer resources, the development of packet switching in the 1960s and the design of computer networks for data communication. The set of rules (communication protocols) to enable i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
