Analog Video: Signal that consists of a continuos waveform, as opposed to digital or discreet signals. It was the predominant transmission mode for videoconferencing until the 1980s and still is for commercial television. An analog video signal requires a hig her bandwidth than a digital signal. BRI: Basic Rate Interface. An ISDN subscriber line consisting of two 64 kbps channels and one 16 kbps D channel, used for both data and signaling purposes. Bridge: A piece of video networking equipment that allows multiple sites to participate in a single video conference. It is also known as a Multipoint Control Unit (MCU) Compressed Video: Video signal that results when a compression algorithm digitizes the key elements of a picture in digital form, thus reducing the required transmission bandwidth. Identifying what we do as compressed video can often be helpful in clarifying that we are not using satellite or other analog transmission. Data Conferencing: Real-time communications that allow users to work together using PC-based information. Includes capabilities such as "application sharing," whereby users can simultaneously see and edit a computer file, and "shared whiteboard" for marking up info rmation from a computer file. May or may not be accompanied by video conferencing. Dedicated Line: Connection between two locations on a fixed fee basis. Dedicated Network: Permanent connection between various sites at a fixed cost, regardless of the amount of traffic. Desktop Videoconferencing: Attachment for a personal computer that allows an individual to videoconference directly from a desk to another location within the building or through a network to a remote site. These are becoming more popular and cheaper as is the rest of the videoconferencing equipment. The expectation is that we will all have these in our homes so you can see your grandkids when you call them. Frames per second: Our current maximum, and preferable operating rate, is 30 frames per second. Many systems are operating at 15 frames per second. This is acceptable though not as smooth. CU-SeeMe, an inexpensive option for conferencing that utilizes computers already in place, operates at about 6 frames per second. H.320: This is the standard for videoconferencing adopted by the International Telecommunications Union. Hub: A collection of video networking equipment that allows several videoconferences, both point to point and multipoint, to go on at the same time. I-Mux (Inverse Multiplexer): A device that creates a single higher-speed transmission by combining and synchronizing two or more channels. ISDN: Integrated Services Digital Network: provides digital connections between the customer and network interface. Used for videoconferencing and other high data transfer demands. Lines must be drawn directly to the site but then connect into the already existing telecommunications infrastructure. Kbps: Kilobits per second. Our current maximum data transmission is 384 kbps. Multiplexer: Electronic equipment that allows two or more signals to pass over one communications circuit. PRI: Primary Rate Interface. An ISDN subscriber line consisting of 23 64 kbps B channels and one 64 kbps D channel used for signaling. Switched 56/64: A service providing the ability to dial a temporary connection in order to transport high-speed voice, data, or video at 56 or 64 kbps over the public network. T-1: Point-to-point communications line. This is what we have to Baylor. © 1997 CORD vtcinfo@cord.org Center for Occupational Research and Development: P.O. Box 21689 Waco, Texas 76702-1689 601 Lake Air Drive Waco, Texas 76710-5841 Phone: 800-231-3015 Fax: 817-776-3906 Back to VTC index page