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Part One: Video Conferencing

1. A Definition

The term videoconferencing is a confusing one. Some commercial companies (AT & T in the States) are now advertising “videoconferencing" as a new technology. The fact is that videoconferencing is a function which can be hosted on a variety of technologies and has been for some years. It is not a technology in itself. In America, the term is fast becoming defined as any use of television to join people in some live interaction. However, the term is actually applied to a wide range of situations from live video lecturing to large audiences, to a point-to-point, individual-to-individual desktop PC chats. One possible categorisation is into large scale and small scale. The majority of large scale set-ups are currently satellite-based in the form of “interactive television” i.e., one-way video, two-way audio. This allows for broadcast from a central point to many different locations regardless of distance. Small scale refers to compressed video for meetings between relatively few points for small meetings. A technology used for this function is ISDN. ISDN promises to make two-way video equally as cost effective, with potential for greater interactivity.

Traditional video conferencing requires expensive, fixed delivery and reception installations and high transmission costs over full band width analogue video channels or high capacity digital channels. Such high grade services allow full two-way audio and video communication between several locations at a price; a more common configuration is that of Interactive TV (Full service out, audio only in). High costs and lack of flexibility has limited the past educational uses in the past to research projects . Recent developments in video compression and codec technology is increasing the use of relatively low bandwidth ISDN using a variety of display formats.

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