History of videotelephony

" combination videophone-television, conceptualized by George du Maurier and published in Punch magazine. The drawing also depicts then-contemporary speaking tubes, used by the parents in the foreground and their daughter on the viewing display (1878). Barely two years after the telephone was first patented in the United States in 1876 by Alexander Graham Bell, an early concept of a combined videophone and wide-screen television called a telephonoscope was conceptualized in the popular periodicals of the day. It was also mentioned in various early science fiction works such as Le Vingtième siècle. La vie électrique (The 20th century. The electrical life) and other works written by Albert Robida, and was also sketched in various cartoons by George du Maurier as a fictional invention of Thomas Edison. One such sketch was published on December 9, 1878, in Punch magazine. In April 1891, Dr. Bell actually did record conceptual notes on an "electrical radiophone", which discussed the possibility of "seeing by electricity" using devices that employed tellurium or selenium imaging components. Bell went on to later predict that: "...the day would come when the man at the telephone would be able to see the distant person to whom he was speaking." The discoveries in physics, chemistry and materials science underlying video technology would not be in place until the mid-1920s, first being utilized in electromechanical television. More practical "all-electronic" video and television would not emerge until 1939, but would then suffer several more years of delays before gaining popularity due to the onset and effects of World War II. The compound term "videophone" slowly entered into general usage after 1950, although "video telephone" likely entered the lexicon earlier after video was coined in 1935. Prior to that time there appeared to be no standard terms for "video telephone", with expressions such as "sight-sound television system", "visual radio" and nearly 20 others (in English) being used to describe the marriage of telegraph, telephone, television and radio technologies employed in early experiments. Among the technological precursors to the videophone were telegraphic image transmitters created by several companies, such as the wirephoto used by Western Union, and the teleostereograph developed by AT&T's Bell Labs, which were forerunners of today's fax (facsimile) machines. Such early image transmitters were themselves based on previous work by Ernest Hummel and others in the 19th century. By 1927 AT&T had created its earliest electromechanical television-videophone called the ikonophone (from Greek: "image-sound"), which operated at 18 frames per second and occupied half a room full of equipment cabinets. An early U.S. test in 1927 had their then-Commerce Secretary Herbert Hoover address an audience in New York City from Washington, D.C.; although the audio portion was two-way, the video portion was one-way with only those in New York being able to see Hoover. By 1930, AT&T's "two-way television-telephone" system was in full-scale experimental use. The Bell Labs' Manhattan facility devoted years of research to it during the 1930s, led by Dr. Herbert Ives along with his team of more than 200 scientists, engineers and technicians, intending to develop it for both telecommunication and broadcast entertainment purposes. There were also other public demonstrations of "two-way television-telephone" systems during this period by inventors and entrepreneurs who sought to compete with AT&T, although none appeared capable of dealing with the technical issues of signal compression that Bell Labs would eventually resolve. Signal compression, and its later sibling data compression were fundamental to the issue of transmitting the very large bandwidth of low-resolution black and white video through the very limited capacity of low-speed copper PSTN telephone lines (higher resolution colour videophones would require even far greater capabilities). After the Second World War, Bell Labs resumed its efforts during the 1950s and 1960s, eventually leading to AT&T's Picturephone. == Closed-circuit videophone systems: 1936–1940 ==

In early 1936, the first public video telephone service, Germany's Gegensehn-Fernsprechanlagen (visual telephone system), was developed by Dr. Georg Schubert, who headed the development department at the Fernseh-AG, a technical combine for television broadcasting technology. Two closed-circuit televisions were installed in the German Reichspost (post offices) in Berlin and Leipzig and connected together via a dedicated broadband coaxial cable to cover the distance of approximately 160 km (100 miles). The system's opening was inaugurated by the Minister of Posts Paul von Eltz-Rübenach in Berlin on March 1, 1936, who viewed and spoke with Leipzig's chief burgomaster. Schubet's higher-performance system employed a Nipkow disk flying-spot scanner for its transmitter (a form of mechanical television) and a 20 cm (8 inch) cathode-ray display tube with a resolution of 150 lines (180 lines in later versions) running at 25 frames per second. After a period of experimentation, the system entered public use and was soon extended with another 160 km (100 miles) of coaxial cable from Berlin to Hamburg, and then in July 1938 from Leipzig to Nuremberg and Munich. Point-to-point video calling required swapping connections on a telephone switchboard. The system eventually operated with more than 1,000 km (620 miles) of coaxial cable transmission lines. The videophones were integrated within large public videophone booths, with two booths provided per city. Calls between Berlin and Leipzig cost RM3½, approximately one sixth of a British pound sterling, or about one-fifteenth of the average weekly wage. The video telephone equipment used in Berlin was designed and built by the German Post Office Laboratory. Videophone equipment used in other German cities were developed by Fernseh A.G., partly owned by Baird Television Ltd. of the U.K., inventors of the world's first functional television. During its life the German system underwent further development and testing, resulting in higher resolutions and a conversion to an all-electronic camera tube transmission system to replace its mechanical Nipkow scanning disc. While the system's image quality was primitive by modern standards, it was deemed impressive in contemporary reports of the era, with users able to clearly discern the hands on wristwatches. The videophones were offered to the general public, which had to visit special post office Fernsehsprechstellen (video telephone booths, from "far sight speech place") simultaneously in their respective cities, but which at the same time also had Nazi political and propagandistic overtones similar to the broadcasting of the 1936 Olympic Games in Berlin. The German post office announced ambitious plans to extend their public videophone network to Cologne, Frankfurt and Vienna, Austria, but expansion plans were discontinued in 1939 with the start of the Second World War. After Germany subsequently became fully engaged in the war its public videophone system was closed in 1940, with its expensive inter-city broadband cables converted to telegraphic message traffic and broadcast television service. A similar commercial post office system was also created in France during the late-1930s. The Deutsche Bundespost postal service would decades later develop and deploy its BIGFON (Broadband Integrated Glass-Fiber Optical Network) videotelephony network from 1981 to 1988, serving several large German cities, and also created one of Europe's first public switched broadband services in 1989. == AT&T Picturephone Mod I: 1964–1970 ==

In the United States, AT&T's Bell Labs conducted extensive research and development of videophones, eventually leading to public demonstrations of its trademarked "Picturephone" product in the 1960s. Its large Manhattan experimental laboratory devoted years of technical research during the 1930s, led by Dr. Herbert Ives along with his team of more than 200 scientists, engineers and technicians. The images were captured by the Picturephone's compact Vidicon camera and then transferred to a storage tube or magnetic drum for transmission over regular phone lines at two-second intervals to the receiving unit, which displayed them on a small cathode-ray television tube. The more advanced Picturephone "Mod I" (Model No. 1) had public evaluation displays at Disneyland and the 1964 New York World's Fair, with the first transcontinental videocall between the two venues made on April 20, 1964. The system was the result of decades of research and development at Bell Labs, its principal supplier, Western Electric, plus other researchers working under contract to the Bell Labs. However the use of reservation time slots and their cost of US$16 (Washington, D.C., to New York) to $27 (New York to Chicago) (equivalent to $118 to $200 in 2012 dollars) for a three-minute call at the public videophone booths greatly limited their appeal resulting in their closure by 1968. == First video conferencing service: 1970 ==

AT&T developed a refined Picturephone throughout the late 1960s, resulting in the "Mod II" (Model No. 2), which served as the basis for AT&T's launch of the first true video conferencing service. Unlike earlier systems, in which people had to visit public videophone booths, any company or individual could pay to be connected to the system, after which they could call anyone in the network from their home or office. The inaugural video call occurred on June 30, 1970, between Pittsburgh Mayor Peter Flaherty and Chairman and CEO John Harper of Alcoa. Picturephone Mod II The Picturephone's video bandwidth was 1 MHz with a vertical scan rate of 30 Hz, horizontal scan rate of 8 kHz, and about 250 visible scan lines. The equipment included a speakerphone (hands free telephone), with an added box to control picture transmission. Each Picturephone line used three twisted pairs of ordinary telephone cable, two pairs for video and one for audio and signaling. Cable amplifiers were spaced about a mile apart (1.6 kilometres) with built-in six-band adjustable equalization filters. 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. with prices starting at US$1,500 (approximately $ in current dollars) and later dropping to $1,000 ($ in current dollars), marketed by its Global VideoPhone Systems unit. The VideoPhone 2500 was designed to provide low-frame rate compressed color video on ordinary Plain Old Telephone Service (POTS) lines, circumventing the significantly higher cost ADSL telephone service lines used by several other videoconferencing manufacturers. It was limited by analog phone line connection speeds of about 19 Kilobits per second, the video portion being 11,200 bit/s, and with a maximum frame rate of 10 frames per second, but typically much slower, as low as a third of a video frame per second. The VideoPhone 2500 used proprietary technology protocols, including AT&T's Global VideoPhone Standard (GVS). Again, AT&T met with very little commercial success, selling only about 30,000 units, mainly outside the United States. Despite AT&T's various videophone products meeting with commercial failure, they were widely viewed as technical successes which expanded the limits of the telecommunications sciences in several areas. Its videotelephony programs were critically acclaimed for their technical brilliance and even the novel uses they experimented with. The research and development programs conducted by Bell Labs were highly notable for their beyond-the-state-of-the-art results produced in materials science, advanced telecommunications, microelectronics and information technologies. AT&T's published research additionally helped pave the way for other companies to later enter the field of videoconferencing. The company's videophones also generated significant media coverage in science journals, the general news media and in popular culture. The image of a futuristic AT&T videophone being casually used in the science fiction film 2001: A Space Odyssey, became iconic of both the movie and, arguably, the public's general view of the future. == Other early videophones: 1968–1984 ==

Beginning in the late 1960s, several countries worldwide sought to compete with AT&T's advanced development of its Picturephone service in the United States. However such projects were research and capital intensive, and fraught with difficulties in being deployed commercially. France France's post office telecommunications branch had earlier set up a commercial videophone system similar to the German Reichspost public videophone system of the late 1930s. Their initial attempt at a first generation commercial videophone later led to the British Telecom Relate 2000, which was released for sale in 1993, costing between £400-£500 each. The Relate 2000 featured a flip-up colour LCD screen operating at a nominal rate of 8 video frames per second, which could be depressed to 3-4 frames per second if the PSTN bandwidth was limited. In the era prior to low-cost, high-speed broadband service, its video quality was found to be generally poor by the public with images shifting jerkily between frames, due to British phone lines that generally provided less than 3.4 kHz of bandwidth. Its second generation videophone thus also proved to be commercially unsuccessful, similar to AT&T's VideoPhone 2500 of the same time period. == Digital videotelephony: 1985–1999 ==

This time period saw the research, development and commercial roll-out of what would become powerful video compression and decompression software codecs, which would eventually lead to low cost videotelephony in the early 2000s. Video compression Advances in video compression allowed digital video streams to be transmitted over the Internet, which was previously difficult due to the impractically high bandwidth requirements of uncompressed video. To achieve Video Graphics Array (VGA) quality video (480p resolution and 256 colours) with raw uncompressed video, it would require a bandwidth of over 92Mbps. A common compression technique used to significantly reduce bandwidth requirements in videotelephony and videoconferencing is the discrete cosine transform (DCT), developed by Nasir Ahmed, T. Natarajan and K. R. Rao in 1973. The DCT algorithm was the basis for the first practical video coding standard that was useful for online videoconferencing, H.261, standardised by the ITU-T in 1988, and subsequent H.26x video coding standards. Vistium was AT&T’s desktop videoconferencing system designed to work over ISDN or Switched 56. AT&T discontinued Vistium in late 1995. Multipoint control units provided the capability to link three or more desktop videoconferencing users. The WorldWorx service, announced in mid-1994, was AT&T’s video network service offering. By July, 1995, WorldWorx announced the world’s first service to make real-time voice, video and data communications possible for multiple participants on one call. The business unit was led by Ernest G. DeNigris, a former member of the AT&T Picturephone team. Intel and ProShare In May 1992, Intel formally began a videoconferencing project. One team focused on data conferencing, another on PC telephony and another on adding videoconferencing to PC telephony. Intel combined these teams into what became the Personal Conferencing Division headed by Patrick W. Gelsinger who would one day lead the company. There was considerable debate within Intel whether to emphasize videoconferencing or audio/data conferencing in that many business users were not interested in seeing each other through video. Ultimately, Intel decided to push video along with audio and data conferencing, because video would more significantly increase demand for future generations of Intel processors. In early 1994, Intel began shipping ProShare, a personal videoconferencing product that ran over ISDN and allowed up to twenty-four people to simultaneously participate. In mid-1996, Intel introduced the Intel Video Phone with ProShare technology running over POTS and required a 133-MHz Pentium processor-based PC and specialized modem. Intel also introduced its Internet Video Phone in 1996 which supported the H.323 international standard for real-time voice, video and data communication over packet-based networks. One team focused on data conferencing, another on PC telephony and another on adding videoconferencing to PC telephony. Intel combined these teams into what became the Personal Conferencing Division headed by Patrick W. Gelsinger who would one day lead the company. There was considerable debate within Intel whether to emphasize videoconferencing or audio/data conferencing in that many business users were not interested in seeing each other through video. Japanese videophones In Japan the Lumaphone was developed and marketed by Mitsubishi in 1985. The project was originally started by the Ataritel division of the Atari Video Game Company in 1983 under the direction of Atari's Steve Bristow. Atari then sold its division to Mitsubishi Electric in 1984. The Lumaphone was marketed by Mitsubishi Electric of America in 1986 as the Luma LU-1000, costing US$1,500, Much later the Kyocera Corporation, an electronics manufacturer based in Kyoto, conducted a two-year development campaign from 1997 to 1999 that resulted in the release of the VP-210 VisualPhone, the world's first mobile colour videophone that also doubled as a camera phone for still photos. The camera phone was the same size as similar contemporary mobile phones, but sported a large camera lens and a 5 cm (2 inch) colour TFT display capable of displaying 65,000 colors, and was able to process two video frames per second. The 155 gram (5.5 oz.) camera could also take 20 photos and convey them by e-mail, with the camera phone retailing at the time for 40,000 yen, about US$325 in 1999. The VP-210 was released in May 1999 and used its single front-facing 110,000-pixel camera to send two images per second through Japan's PHS mobile phone network system. Although its frame rate was crude and its memory is considered tiny in the present day, the phone was viewed as "revolutionary" at the time of its release. Saburi also stated that their R&D section had "nourished [the idea] for several years before" they received project approval from their top management which had encourage such forward-thinking research, because they "also believed that such a product would improve Kyocera's brand image." Their research showed that a "cell phone with a camera and color display provided a completely new value for users, It could be used as a phone, a camera and a photo album". Technical challenges handled by about a dozen engineers at Kyocera over the two year development period included the camera module's placement within the phone at a time when electronic components had not been fully reduced in size, as well as increasing its data transmission rate. After its release the mobile video-camera phone was commercially successful, spawning several other competitors such as the DDI Pocket, and one from Vodafone K.K. == Videoconferencing and videophone improvements: post-2000 ==

Significant improvements in video call quality of service for the deaf occurred in the United States in 2003 when Sorenson Media Inc. (formerly Sorenson Vision), a video compression software coding company, developed its VP-100 model stand-alone videophone specifically for the deaf community. It was designed to output its video to the user's television in order to lower the cost of acquisition, and to offer remote control and a powerful video compression codec for unequaled video quality and ease of use with a video relay service (VRS). Favourable reviews quickly led to its popular usage at educational facilities for the deaf, and from there to the greater deaf community. Coupled with similar high-quality videophones introduced by other electronics manufacturers, the availability of high speed Internet, and sponsored video relay services authorized by the U.S. Federal Communications Commission in 2002, VRS services for the deaf underwent rapid growth in that country. The videoconference linked Boeing 737 business jet passengers flying 37,000 feet above Arizona with participants at Boeing’s annual investors’ conference in St. Louis. The demonstration via satellite ran at a speed of 256 kilobits per second. == Ubiqitous videoconferencing and the end of the videophone ==

The videophone as a distinct product concept ceased to exist in the late 2000s as the convergence of multiple factors made video calling functionality ubiquitous across a wide range of computing devices. The widespread availability of Internet access, the exponential increase in processing power of modern CPUs, increasingly efficient video codecs, and the introduction of cheap webcams and large-screen Internet-connected video-capable cameraphones such as the iPhone in 2007 led to a virtuous spiral which allowed the integration of video calling as a universal feature of modern mobile phones, laptop and desktop computers. Rather than requiring a distinct device, videoconferencing, and by extension videotelephony, became an application software feature with the introduction of video calling services such a Google Meet, Zoom and Microsoft Teams. == See also ==