RealPresence Collaboration Server (RMX) 1500/1800/2000/4000 Administrator’s Guide
Polycom®, Inc. 20
SVC-based Conferencing
The SVC-Based conferencing mode provides video without transcoding by the MCU, hence requiring less
video resources while providing better error resiliency and lower latency.
Using the SVC video protocol, SVC conferences provide video bit streams at different resolutions, frame
rates and line rates to SVC-enabled endpoints with various display capabilities and layout configurations.
In the SVC-based conference, each SVC-enabled endpoint transmits multiple bit streams, called
simulcasting, to the Polycom® RealPresence® Collaboration Server. Simulcasting enables each endpoint
to transmit at different resolutions and frame rates such as 720p at 30fps, 15fps, and 7.5fps, 360p at 15fps
and 7.5fps, and 180p at 7.5fps.
The Polycom SVC-enabled endpoints (such as Polycom® RealPresence® Desktop and Polycom®
RealPresence® Mobile) compose the layout according to their layout settings and video capabilities. This
enables the MCU to send or relay the selected video streams to each endpoint without processing the video
streams and sending the composite video layout to the endpoints.
SVC video streams and Layouts
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The video streams displayed in the conference layout on each endpoint is obtained from the different
streams received from each of the endpoints displayed in the layout. Depending on the size of the video cell
in the configured layout, the endpoint requests the video stream in the required resolution from the
RealPresence Collaboration Server. The higher the display quality and size, the higher the requested
resolution will be sent to the endpoint. The endpoint creates the displayed layout from the different video
streams it receives.