Presentation on theme: "The Picturephone: Basis for Video/Audio Distance Learning Gail Palumbo July 2006 Princeton University Teachers As Scholars."— Presentation transcript:
The Picturephone: Basis for Video/Audio Distance Learning Gail Palumbo July 2006 Princeton University Teachers As Scholars
The Beginnings The seed for Full-Motion Video Distance Learning started with Video Conferencing The basis for Video Conferencing was the Telephone
"This 'telephone' has too many shortcomings to be seriously considered as a means of communication. The device is inherently of no value to us." -- Western Union internal memo, 1876.
Engineers at Bell Laboratories began discussing the concept of simultaneous transmission of video and voice over telephone lines in the 1920's. In 1927, the Bell Telephone System sent live television images of Herbert Hoover, then Secretary of Commerce, over telephone lines from Washington, D.C. to an auditorium in Manhattan, N.Y. This was the first public demonstration in the United States of long-distance video transmission.
Video Conferencing 1956: AT&T builds the first Picturephone test system 1964: AT&T introduces Picturephone at the World's Fair, New York 1970: AT&T offers Picturephone for $160 per month
The Bell System (AT&T/Western Electric) PicturePhone (developed in Bell Labs as a prototype in 1956, but never test marketed until the early 1960's) never became popular after it was briefly offered commercially in Chicago.
The first "PicturePhone" was completed by Bell Laboratory engineers in 1956. This first system was crude and cumbersome and required three standard wire pairs to operate: one pair to carry the video transmission, one pair to carry video reception, and the third to carry the audio signal. Requiring 1,000,000 Hertz of bandwidth, the PicturePhone video signal exceeded by more than 300 times the bandwidth allotted to a typical telephone voice signal.
(about 1962) Joseph A. Mazzeo of Bell Telephone Laboratories removes one of the circuit packages in the experimental PICTUREPHONE system. The comparatively small size of the visual telephone, the PICTUREPHONE is made possible by the development of modern circuits using transistors and other miniature components.
The PicturePhone was connected to the Central Office via 3 standard wire pairs (for comparison, a regular telephone line uses a single wire pair). One pair carried the 1 MHz PicturePhone video signal in one direction, the other carried video the in the opposite direction. These had to be specially equalized to carry the signal but were still otherwise just ordinary telephone wire. The third pair carried the normal 2-way voice call plus carried the TouchTone dialing to set up the call. A PicturePhone Central Office had a second switch (an electromechanical "crossbar" switch in those days!) operating in parallel to the regular switch for those making PicturePhone calls. That takes care of local calls. The fun comes when a call has to be connected to someone served via another Central Office. Telephone calls are multiplexed together to go from one office to another. Many calls share the same communications system whether microwave, coaxial cable, or (nowadays) fiber optic is the medium. Even when offices are connected via ordinary wire pairs many calls share the same wires. A voice channel is allotted only 3000 Hz (this is after all telephony, not 20,000 Hz high-fidelity audio!) for each direction. But a PicturePhone video signal takes 1,000,000 Hz. That's 333 times the bandwidth! A few video calls would fill up all available bandwidth.
By 1964, a somewhat improved version of the PicturePhone, dubbed the "Mod 1," had been developed and was debuted at the New York World's Fair. To test public reaction to the PicturePhone, visitors were invited to place calls between special exhibits of the PicturePhone at the World's Fair and Disneyland. Survey results indicated that most people did not like PicturePhone. The controls were awkward and the picture was small. Moreover, most people were not comfortable with the idea of being seen during a phone conversation.
However, the system's developers at Bell Laboratories were convinced that PicturePhone was viable and could find a market. AT&T inaugurated commercial PicturePhone service between New York City, Chicago, and Washington, D.C., June 24, 1964, with a call from Lady Bird Johnson, wife of President Linden Johnson, in Washington; to Dr. Elizabeth A. Wood of Bell Laboratories in New York City. A three-minute PicturePhone call from Washington to New York City cost $16. The most expensive connection, between New York City and Chicago, cost $27 for three minutes. This inaugural PicturePhone service never caught the attention of consumers.
"A logical extension of today's telephone service...BELL SYSTEM INTRODUCES PICTUREHONE SERVICE... both ends of telephone conversation are pictures; people phone by appointment from family-type booths in attended centers. Bell System PICTUREPHONE service now lets callers see as well as talk on the telephone. And 'handsfree if they wish'. For the first time people can make a visual telephone call to another city-the latest example of the research, invention and development that are constantly providing the communications we provide. The new service is being offered in the cities listed ar the left. Bell Systems attendants at each local center help callers enjoy prearranged face to face visits with friends and relatives in either of the other cities." (the cities are New York, Chicago, Washington)
The Bell System estimated three million PicturePhone units would be operating in homes and offices by the mid- 1980s, bringing in a combined revenue of $5 billion a year. Initial reaction to PicturePhone had been very positive. However, these positive marketing reactions were soon dampened by the realities of cost and the hesitation of people to be accidentally seen by others in the private affairs of their homes. AT&T abandoned its plans to market the Mod II in 1973.
In January 1992, AT&T executives again predicted the success of a videophone system with the introduction of the AT&T VideoPhone 2500-the first full-color, home video phone system to use standard home telephone lines. During the system's debut, Robert Kavner, AT&T group executive for AT&T Communications Products, said, "This is the way people want to communicate. The time is right. The price is right. The technology is right."
Video phones finding niche after 40 years in development by Al Moyers Air Force Communications Agency Office of History (http://infosphere.safb.af.mil/~rmip/97dec/intercom.htm) Note: The original web link above is no longer valid. I managed to find a text file of this article on another server at: http://zia.hss.cmu.edu/miller/eep/news/video2.ne.txt http://zia.hss.cmu.edu/miller/eep/news/video2.ne.txt The Air Force is testing video telephones at locations both in the United States and overseas to provide "video morale calls" for deployed members. "I have never seen a better morale booster," was the report of one Air Force first sergeant during a recent test of video telephone technology at Incirlik AB, Turkey. The video phone concept is actually more than four decades old, but new low-cost technologies are providing the Air Force a rare opportunity to permit families and deployed airmen to be able to see, as well as talk, to one another.
AT&T executives reported that the video phone would become as popular as cordless and cellular phones. Yet, a large market has yet to be found. According to the calculations of telecommunications author Stephen J. Maudsley, the great decrease in the cost of video telephones is due to the continued development of silicon technology. Maudsley reports the cost of a video telephone in the 1960's was nearly $500,000. The AT&T VideoPhone 2500 was introduced in 1992 at a cost of approximately $1500 and within a year was selling for less than $1000. The video telephone system being tested by the Air Force sells for about $500 for each unit. This dramatic increase in savings, according to Maudsley, comes from two areas-the integration of functions and the compression of images- associated with the continued decrease in the size of electronic devices.
The functions required for video phone operation have been integrated onto fewer pieces of silicon. This is a direct result of the decrease in the size of component transistors. During the early period of video telephone development, the smallest feature on a silicon chip was about 10 microns. Currently, silicon chips are being manufactured with features as small as.3 microns. Video compression ratios have also improved to increase the rate of image transmission from PicturePhone's one frame every two seconds to the present state-of-the-art 20 frames per second. By comparison, broadcast television transmits at 30 frames per second.
Now, video telephones have taken two distinct venues. Seemingly, the larger share of the industry was concentrating its efforts in personal computer-based systems, or desktop video teleconferencing technology, which requires computer networks. The smaller effort was aimed at the video phone- through-your-television market which requires no more than a television, a video telephone, and POTS, the industry acronym for plain old telephone service. The Air Force is testing the latter. According to Col. David L. Rakestraw, director of technology at the Air Force Communications Agency, "because they are so easy to set up and use, video phones are an excellent way for the Air Force to add a video dimension to phone calls home."
Moreover, the television-based systems cost no more for line transmission than a standard voice call. Whether consumers on a large scale will finally be attracted to video telephone technology remains to be seen. The technology does seem to have found a niche among those Air Force members who have taken part in the Air Force trials. After seeing and speaking to his wife in Hawaii from his deployed location in Turkey, SSgt. Lionel Price remarked, "I have been blessed to take part in this."
"Someday you'll be a star!" was one of the advertising slogans the Bell System used decades ago to try to promote this high tech and futuristic communications device called the "PicturePhone". But no matter how much the Bell System tried, it was one of the most visible flops in communications technology history.
The picturephone limped along briefly and then was quietly pulled at a loss of $1 billion.
Distance Communication 1971: Ericsson demonstrates the first trans-atlantic video telephone (LME) call – commercial use first realized 1973 Dec: ARPAnet packet voice experimentsARPAnet 1976 Mar: Network Voice Protocol (NVP), by Danny Cohen, USC/ISI 1981 Jul: Packet Video Protocol (PVP), by Randy Cole, USC/ISI
CU-SeeMe 1992 Macintosh Based at first 1996 International Telecommunications Union (ITU) began developing standards 2001 Worlds first transatlantic tele-surgery 2003 Interactive classrooms