you history know video chat
conferencing ? if you don’t know wikipedia will explain and told you about
videoconferencing, this is history :
uses telecommunications of audio and video to bring people at different sites
together for a meeting. This can be as simple as a conversation between two
people in private offices (point-to-point) or involve several sites
(multi-point) with more than one person in large rooms at different sites.
Besides the audio and visual transmission of meeting activities,
videoconferencing can be used to share documents, computer-displayed
information, and whiteboards.
analog videoconferences could be established as early as the invention of the
television. Such videoconferencing systems usually consisted of two
closed-circuit television systems connected via coax cable or radio. An example
of that was the German Reich Postzentralamt (Post Office) network set up in
Berlin and several other cities from 1936 to 1940.
the first manned space flights, NASA used two radiofrequency (UHF or VHF)
links, one in each direction. TV channels routinely use this kind of
videoconferencing when reporting from distant locations, for instance. Then
mobile links to satellites using specially equipped trucks became rather
technique was very expensive, though, and could not be used for applications
such as telemedicine, distance education, and business meetings. Attempts at
using normal telephony networks to transmit slow-scan video, such as the first
systems developed by AT&T, failed mostly due to the poor picture quality
and the lack of efficient video compression techniques. The greater 1 MHz
bandwidth and 6 Mbit/s bit rate of Picturephone in the 1970s also did not cause
the service to prosper.
To be continued ....