VCON HD3000, Руководство пользователя, Страница: 87 / 164

VCON HD3000 User’s Guide 75
7 M
ULTI
P
OINT
C
ONFERENCING
- HD3000’
S
E
MBEDDED
MCU
HD3000 includes an MCU (Multipoint Control Unit) embedded within. An MCU
is a device which provides conferencing between more than two parties. The MCU
joins up to up to 4 participants (Chair + 3 others) at 384 Kbps, or 3 participants at
768 Kbps. When the Chair, or moderator, transmits, the HD3000’s MCU
multiplexes the audio and video, and then sends the resulting streams to all the
others in the session.
The HD3000’s MCU joins the participants and applies Voice-activated Switching
to display the video, showing the dominant speaker, and hearing everyone’s audio.
A single participant may also be a cascaded MCU , which refers to another HD3000
that has joined two other participants, in addition to the Chair (see “Cascaded
Multipoint Conferences” on page 79 ).
The Speed Matching feature allows conference participants to connect at different
data rates, regardless of the data rate used by anyone else. In the following
illustration, three participants connected at varying rates.
The HD3000 can process and convert various video and audio codecs during a
conference (
Transcoding ). If the HD3000 sends video and audio using the highest
quality codec, the conference proceeds, regardless of the other codecs being used
by the other participants.