PictureTel Concorde 4500 Servicing Manual page 210

multiplexer
A device that divides the bandwidth of a channel by frequency or time to enable multiple
devices to share the channel.
multipoint bridge
A set of highly integrated, software-controlled data communications components that
enable more than two videoconference sites to participate in a videoconference.
multipoint videoconference
A videoconference in which more than two sites can participate at one time.
National Television System Committee (NTSC)
A television broadcast standard used in the United States, Japan, and parts of South America,
based on 30 frames per second video transmission.
Nx56 kbps
A video transmission with speed of multiples (either two, four, or six) of 56 kbps over a single
data line between the VCS and the network equipment.
Nx64 kbps
A video transmission with speed of multiples (either two, four, or six) of 64 kbps over a single
data line between the VCS and the network equipment.
parity
A process for checking whether bits of data have been altered during transmission of that
data. A check may be made for either even parity or odd parity.
Phase Alternate Line (PAL)
A television broadcast standard used in Europe, based on 25 frames per second video
transmission.
pic codes
Codes that allow you to dial onto the lines of a network carrier other than your own. Your
local telephone company can set up your pic codes.
Power-On-Self-Test (POST)
A series of tests performed by the videoconferencing system at power-on. These tests
examine such things as the Video board and the hard disk.
Primary Rate Interface (PRI)
An ISDN interface that supports 23 bearer channels for 1.544 Mbps in the United States and
Japan or 30 bearer channels for 2.048 Mbps in Europe.
Glossary-6