AT&T MERLIN LEGEND Release 2.0 Equipment And Operations Manual page 207

Applications
Video conferences can be started from an easy-to-use control console and can
be as easy to use as a telephone. No special technical expertise is required to
operate the system.
The basic components include
The conference control subsystem—to establish and terminate
connections and allows camera control including pan, tilt, and zoom; and
audio control for volume and privacy.
The video subsystem—includes a full-motion video camera, a video
monitor, and various video switching circuits, May also include an
auxiliary room camera, a document camera, and a video cassette
player/recorder.
The audio subsystem—allows video participants to hear and speak at
the same time. Includes microphones, microphone mixer, an echo
canceller. Microphones may include table top microphones, wired lapel
microphones, and/or wireless hand-held or lapel microphones.
The video codec subsystem—a signal processing computer that
digitizes, merges, and compresses audio and video signal input from the
camera and microphone mixer for transmission to the far-end conference
unit.
These basic components can be integrated into a mobile roll-about console that
can be easily wheeled into a conference room or executive office prior to a
scheduled video conference call. Alternatively, the components can be built-in
to a video conference room.
Additional equipment may be required, for example, an interface converter for
the video codec.
Optional applications can be added to the basic components to enhance the
information being sent back and forth during an interactive broadcast.
See Chapter 5, Data, for additional information about Video Conferencing.
Primary Rate Interface (PRI) Applications
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