Term of the Moment

archive program


Look Up Another Term


Redirected from: continuous presence

Definition: MCU


(1) (MicroController Unit) A computer on a single chip. Operating in cars, appliances, toys and myriad electronic devices, billions of MCUs are manufactured every year. For details, see microcontroller.

(2) (Multipoint Control Unit) A device used to moderate a videoconference of three or more endpoints (users in a single location). In the common "continuous presence" mode, the screen is split into one large and several smaller windows, and the MCU sends the video of the dominant speaker to the large window. "Voice switch" mode has only one window, which is used for the speaker. In "chair mode," a human moderator controls the screen. The MCU's audio bridge mixes the audio from all endpoints. See videoconferencing.




A Complete Videoconferencing Solution
This earlier MCU from Emblaze-VCON supported both H.323 and SIP protocols. It also included a gatekeeper for translating user names into IP addresses, a video PBX for call switching and network management for quality of service (QoS) and bandwidth control. (Image courtesy of Emblaze-VCON, Inc.)