Video Conferencing Glossary

Bandwidth
The amount of data that is actually being sent down the telephone/isdn/network line. This is measured in KBPS
Bridge/External Bridge
See MCU
Camera Presets
Allows predefined camera angles to be programmed into a videoconferencing system
CODEC
Coder Decoder for video signals. Converts analogue video signals to digital signals for transmission over digital circuits, and then converts the digital signals back to analogue signals for display
Continuous Presence
Conference where multiple sites are seen on the screen simultaneously for the entire conference
Document camera
A specialised camera for taking pictures of still images (pictures, graphics, text pages) to be sent as part of a videoconference
Echo Cancellation
Process of eliminating acoustic echo in a videoconferening room. This is a critical component. If echo is not suppressed, the speaker hears their own audio coming back from the far site after a small time delay
H.239 standard
A protocol for document sharing, system dependent and not available from all videoconferencing units
H.323 standard
A video compression standard that allows a wide variety of systems to communicate
Interactive Whiteboard (IWB)
An interactive whiteboard is a device that interprets a projected two dimensional surface that interacts with a computer's desktop. The software mimics the computer's mouse and keyboard. Used to send whiteboard interactions as part of a videoconference
IP (Internet Protocol)
The computer networking protocol used on the internet
IP address
Internet Protocol address - a computer network address
ISDN
Integrated Services Digital Network - telephone network system designed to allow digital transmission of voice and data over ordinary telephone copper wires
KBPS
Kilobytes per secon
KLDC
Kwong Lee Dow Centre
Lecture mode
A conference where a single site (the presenter) is viewed by all other sites. The presenter sees the other sites in Continuous Presence mode
MCU
Multiple Control Unit - (Bridge) a unit that supports videoconferencing with multiple users at the same time. In videoconferencing, a bridge connects three or more sites so that they can simultaneously pass data, voice or video
People + Content
Polycom proprietry presentation protocol
Picture-in Picture (PIP)
A small window on the monitor that displays the image from a video source superimposed on the image being displayed on the full screen
Roll Call
Videoconference administrator conducts a roll call of all connected sites before proceeding with the conference
Transmission Speed
The speed at which the hardware used for conference connects 128Kbps, 256Kbps, 384Kbps
Videoconference
Communication across a network with video and audio contact that may also include data exchange
Voice Switched
A conference where the view automatically switches to the site that is talking (or loudest)