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Encyclopedia > Picturephone

A videophone is a telephone which is capable of both audio and video duplex transmission. The telephone or phone is a telecommunications device which is used to transmit and receive sound (most commonly voice and speech) across distance. ... This article is about compression waves. ... Video is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images which represent scenes in motion. ... In telecommunications, duplex means two-way when referring to communications channels. ...


Early History

AT&T conducted experiments and demonstrations of a Picturephone product and service in the early 1960s. The demo unit was usually in a small oval cabinet on a swivel stand, intended to stand on a desk. Videophones, possibly ATT units , were featured at the Telephone Association of Canada Pavilion (The 'Bell' Pavilion) at Expo 67, an International World's Fair held in Montreal, Canada in 1967. Several demonstration videophone units were available for the Fair-going public to try, who were permitted to make live video calls to recipient volunteers in the United States. Color was not employed. The equipment packaged a Plumbicon camera and a small CRT display in the cabinet. Video bandwidth was 1 MHz with about 200 scan lines. The equipment included a Speakerphone hands free telephone, with an added box to control picture transmission. Cable amplifiers were spaced about a mile apart (1.6 Kilometers) using ordinary twisted pair cables with built-in six-band equalizers. For distances of more than a few miles, the signal was digitized at 2 MHz and 3 bits per sample DPCM, and transmitted on a T-2 carrier. This article describes the present AT&T Inc. ... The 1960s decade refers to the years from January 1, 1960 to December 31, 1969, inclusive. ... Man and His World redirects here - for the 1990 animated documentary feature film by Bruno Bozzetto, see Man and His World. ... Motto: Concordia Salus Coordinates: Country Canada Province Québec Founded 1642 Established 1832 Mayor Gérald Tremblay Area    - City 366. ... 25 Pair Color Code Chart 10BASE-T UTP Cable Twisted pair cabling is a common form of wiring in which two conductors are wound around each other for the purposes of cancelling out electromagnetic interference known as crosstalk. ...


Picturephone was offered to the public in New York City and Washington DC in the early 1970s. The screen was larger than in the original demo units, approximately half a foot (15 cm) square in a roughly cubical cabinet. Picturephone booths were set up in Grand Central Station and elsewhere. With fanfare, Picturephones were installed in offices of Westinghouse and other progressive companies. Hundreds of technicians attended schools to learn to operate the Cable Equalizer Test Set and other equipment, and to install Picturephones. New wideband crossbar switches were designed and installed into 5XB switch offices, this being the most widespread of the relatively modern kinds. Unrelated difficulties at New York Telephone, however, slowed the effort there, and few customers signed up in either city, and the service faded away after a few years. The clock in the Main Concourse © 2004 Metropolitan Transportation Authority Grand Central Terminal (often still called Grand Central Station, although technically that is the name of the nearby post office) is a train station at 15 Vanderbilt Avenue in Midtown Manhattan, New York, a borough of New York City, located... The name Westinghouse can refer to any number of devices and independent businesses that can trace their roots to the work of George Westinghouse: // People George Westinghouse, founder of Westinghouse Electric Corporation Devices Westinghouse air brake. ... A crossbar switch is one of the principal architectures used to construct switches of many types. ... The Number Five Crossbar Switching System, designed by Bell Labs and made by Western Electric was in use in Bell System telephone exchanges from 1948 to the 1980s. ... The New York Telephone Company (NYTel) was organized in 1896, taking over the New York City operations of the American Bell Telephone Company. ...


AT&T sold the VideoPhone 2500 to the general public in 1992 to 1995 with prices starting at US$1500 and later US$1000.[1] It was limited by connecting by analog phone lines at about 19Kbps; the video portion was 11,200bps,[2] with a maximum frame rate of 10 frames per second, but typically much lower. The VideoPhone 2500 used proprietary protocols. ISO 4217 Code USD User(s) the United States, the British Virgin Islands, East Timor, Ecuador, El Salvador, the Marshall Islands, Micronesia, Palau, Panama, Turks and Caicos Islands, and the insular areas of the United States Inflation 3. ...


Protocols

Call Setup

Videoconferencing previously was limited to the H.323 protocol (notably Cisco's SCCP implementation was an exception), however recently a shift towards SIP videophones has occurred. In accordance with the adoption of SIP telephony for home users, videotelephony is also slowly becoming available to home users from a number of hardware and software providers. Closed solutions such as Skype also now provide video. A videoconference (also known as a videoteleconference) is a set of interactive telecommunication technologies which allow two or more locations to interact via two-way video and audio transmissions simultaneously. ... H.323 is an umbrella recommendation from the ITU-T, that defines the protocols to provide audio-visual communication sessions on any packet network. ... SCCP is a proprietary VoIP terminal control protocol originally developed by Selius Corporation. ... The Session Initiation Protocol (SIP) is an application-layer control (signaling) protocol for creating, modifying, and terminating sessions with one or more participants. ... Skype (IPA pronunciation: , rhymes with type) is a peer-to-peer Voice over IP (VoIP) network founded by the entrepreneurs Niklas Zennström and Janus Friis, also founders of the file sharing application Kazaa. ...


Another protocol used by videophones is H.324. Videophones that work on regular phone lines typically use H.324, but the bandwidth is limited by the modem to around 33Kbps, limiting the video quality and framerate. A slightly modified version of H.324 called 3G-324M defined by 3GPP is also used by some cellphones that allow video calls, typically for use only in UMTS networks. H.324 is an ITU-T recomendation for voice, video and data transmission over regular analog phone lines. ... 3G-324M is the 3GPP umbrella protocol for video telephony in 3GPP mobile networks. ... The 3rd Generation Partnership Project (3GPP) is a collaboration agreement that was established in December 1998. ... Universal Mobile Telecommunications System (UMTS) is one of the third-generation (3G) mobile phone technologies. ...


Video Compression

Main article: Video compression
The most commonly used video codecs are H.263 and H.264. Skype uses the proprietary protocol VP7. Video compression refers to making a digital video signal use less data, without noticeably reducing the quality of the picture. ... A Codec is a device or program capable of performing encoding and decoding on a digital data stream or signal. ... H.263 is a video codec designed by the ITU-T as a low-bitrate encoding solution for videoconferencing. ... H.264 is a high compression digital video codec standard written by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG) as the product of a collective partnership effort known as the Joint Video Team (JVT). ... TrueMotion VP7 is a video codec developed by On2 Technologies as a successor to earlier efforts such as VP3, VP5 and TrueMotion VP6. ...


Current use

Videotelephony is most prominently used in large corporate conferencing setups, and is supported by systems such as Cisco CallManager. Other companies such as Tandberg, Radvision, and Polycom also offer similar merchandise. CallManager is a Cisco product. ... For other Tandbergs see Tandberg (disambiguation) Tandberg is a manufacturer of videoconferencing systems, located in Oslo, Norway (product development, sales and distribution) and New York City, USA (sales and distribution). ... Radvision Ltd. ... Polycom is a company noted for making expensive teleconferencing and videoconferencing equipment. ...


Today the principles, if not the precise mechanisms of a videophone are employed by many users world-wide in the form of webcam conferences using personal computers, with cheaply available webcams and microphones and free instant messenger programs. Thus an activity that was disappointing as a separate service found a niche as a minor feature of products intended for other purposes. A videophone can be created by using an old or inexpensive computer and dedicating it to run a video softphone. A Creative webcam A web camera (or webcam) is a real-time camera whose images can be accessed using the World Wide Web, instant messaging, or a PC video calling application. ... In computing, a soft phone is software that simulates a real phone and runs on a general purpose computer, rather than a dedicated device. ...


In 2004 Telmex, the biggest telephone service provider in Mexico, introduced Videophone service over regular phone lines (apparently H.324). The service, as of March 2006, had not enjoyed widespread adoption. Telecom Italia supplies LG-Nortel videophones, which also appear to be used by Telmex.

The Picturephone from Pee-Wee's Playhouse.
The Picturephone from Pee-Wee's Playhouse.

Image File history File links Capture02. ... Image File history File links Capture02. ... Pee-wees Playhouse is a childrens television program starring Pee-wee Herman (played by Paul Reubens) that aired on Saturday mornings on CBS. The show originally ran from September 13, 1986 to July 27, 1991, and was enormously popular with both children and adults. ...

Trivia

  • In many science fiction movies and shows that take place in the future, videophones are used as a primary method of communication. Examples of videophones include the Picturephone from Pee-wee's Playhouse and 2001: A Space Odyssey.
  • A device with the same functionality was used by the cartoon character Dick Tracy since the 1930's. Called the "2-way Wrist TV", the fictional detective often uses the phone to communicate with the police headquarters.
  • AT&T VideoPhone 2500 prototypes are visible in the movie Gremlins 2: The New Batch.

Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... For other uses see film (disambiguation) Film refers to the celluliod media on which movies are printed Film — also called movies, the cinema, the silver screen, moving pictures, photoplays, picture shows, flicks, or motion pictures, — is a field that encompasses motion pictures as an art form or as... Pee-wees Playhouse is a childrens television program starring Pee-wee Herman (played by Paul Reubens) that aired on Saturday mornings on CBS. The show originally ran from September 13, 1986 to July 27, 1991, and was enormously popular with both children and adults. ... Dick Tracy is a comic strip detective and a popular character in American pop culture. ... Prototypes or prototypical instances combine the most representative attributes of a category. ...

See also

A Nokia camera phone in use Instantly sharing a picture A Sony Ericsson K750 camera phone in use Philippe Kahn, inventor of the camera phone Philippe Kahn Working on the first camera-phones A camera phone is a mobile phone which has a camera built-in and a server-based... An information appliance (IA) is any device that can process information, signals, graphics, animation, video and audio; and can exchange such information with another IA device. ... A smartphone or sphone is any electronic handheld device that integrates the functionality of a mobile phone, personal digital assistant (PDA) or other information appliance. ... A videoconference (also known as a videoteleconference) is a set of interactive telecommunication technologies which allow two or more locations to interact via two-way video and audio transmissions simultaneously. ...

External links

  • Mobile video players and converters
  • CNN news article: Video phones: Why is no one calling?

Dedicated videophones

  • AuPix
  • Worldgate Ojo
  • Wooksung
  • Grandstream
  • Leadtek
  • LG-Nortel
  • InnoPhone

Softclient videophones

  • AIM Phoneline
  • WigiWigi
  • Kapanga Softphone SIP client for telecom applications

 
 

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