This article may be too long to read and navigate comfortably. Videotelephony logitech group video conferencing system pdf the technologies for the reception and transmission of audio-video signals by users at different locations, for communication between people in real-time.
At the dawn of its commercial deployment from the 1950s through the 1990s, videotelephony also included “image phones” which would exchange still images between units every few seconds over conventional POTS-type telephone lines, essentially the same as slow scan TV systems. The concept of videotelephony was first conceived in the late 1870s in both the United States and Europe, although the basic sciences to permit its very earliest trials would take nearly a half century to be discovered. Simple analog videophone communication could be established as early as the invention of the television. Such an antecedent usually consisted of two closed-circuit television systems connected via coax cable or radio. T, to serve as an adjunct supplementing the use of the telephone. TV channels routinely use this type of videotelephony when reporting from distant locations. This technique was very expensive, though, and could not be used for applications such as telemedicine, distance education, and business meetings.
Videotelephony developed in parallel with conventional voice telephone systems from the mid-to-late 20th century. Only in the late 20th century with the advent of powerful video codecs combined with high-speed Internet broadband and ISDN service did videotelephony become a practical technology for regular use. Videoconferencing systems throughout the 1990s rapidly evolved from very expensive proprietary equipment, software and network requirements to a standards-based technology readily available to the general public at a reasonable cost. With the rapid improvements and popularity of the Internet, videotelephony has become widespread through the deployment of video-enabled mobile phones, plus videoconferencing and computer webcams which utilize Internet telephony.
Technological developments by videoconferencing developers in the 2010s have extended the capabilities of video conferencing systems beyond the boardroom for use with hand-held mobile devices that combine the use of video, audio and on-screen drawing capabilities broadcasting in real-time over secure networks, independent of location. May 19, 2013 when British adventurer Daniel Hughes used a smartphone with a BGAN satellite modem to make a videocall to the BBC from the summit of Mount Everest, at 8,848 m above sea level. Videotelephony can be categorized by its functionality, that is to its intended purpose, and also by its method of transmissions. During the late 1930s the post offices of several European governments established public videophone services for person-to-person communications utilizing dual cable circuit telephone transmission technology.