Video Conferencing technology connects two or more sites with a video and audio signal. Participants at each site can simultaneously see and hear each other via TV monitors.
Studio based conferences uses dedicated rooms, which usually contain a variety of extra specialist equipment. They are suitable for use by individuals or smallish groups (it depends on the exact layout of the room). The University of Edinburgh has four dedicated video conferencing studios, two use ATM technology and two are ISDN based.
Desktop Video conferencing uses small, relatively cheap cameras which generally sit on top of your own monitor.
The video conferencing studios in most Scottish HE institutions make use of a special high speed network (the metropolitan area network, or MAN) which facilitates a high quality conference using a technology called asynchronous transfer mode (ATM)
An alternative type of technology used for video conferencing is ISDN (Integrated Services Digital Network). Typically systems may use ISDN-2 or ISDN-6, using two or six (ISDN telephone) lines respectively. ISDN-6 is markedy better quality, with the video image better synchronised with the audio, and generally giving a clearer picture and sound.