Desktop Video Conferencing Terminology
- Asymmetrical Digital Service Lines - can transmit at 6.144 megabits but only in a single direction.
- Async or Asynchronous is a mode of communication in which participants need not be on the system at the same time in order to interact. Messages, real time data and lessons, may be sent by e-mail, or else be available to all in a bulletin board or web page environment.
- AVP III
- Audio Video Processor (3rd version by AT&T Microelectronics).
- Basic Rate Interface - 3 separate channels: 2B (bearer) and 1D (delta):
2B - support voice, data and image communications
1D - carries call set-up and management information.
- Circuit Switched Data is a high speed dial up for data, video, graphics, and images.
- Channel Service Unit
- Circuit Switched Voice for local and long distance voice calls.
- A program that provides real time audio and video communication over the internet, available from Cornell University.
- Desktop Color Video Camera
- Data Service Unit
- Digital Video Everywhere (specific to vendor, InSoft - OpenDVE - VTC solution)
- Frames Per Second:
TV = 30
C-Phone = 30
- A superset of hypertext which combines hypertext and multimedia.
- Text containing pointers to other text as cross-references, whereas browsers allow the users to deal with pointers in a transparent way.
- International Multimedia Teleconferencing Consortium Inc., a non-profit group consisting of 90 conferencing suppliers.
- Internet Protocol-Multicast is a technique of multicasting on the internet that allows data packets to be passed to multiple selected destinations.
- Internet Realty Chat is a worldwide on-line text-based conferencing system, which allows for multiparty discussions.
- Integrated Services Digital Network:
Integrated - multiple services supported on one line
Services - voice, data, image, graphics
Digital - faster, more reliable transmission; virtually error free.
- International Telecommunications Union
- Local Exchange Carrier
- Multicast Backbone of the Internet is a virtual network of hosts and routers connected to the Internet, communicating using IP-multicast and used for real-time multimedia conferencing.
- Multipoint Constant Presence Architecture
- Multipoint Control Unit displays all speakers.
- MUD Object Oriented allows the manipulation and interaction with Cyber-objects in addition to chatting with other people.
- Multipoint Selective Presence Architecture
- Multipoint Control Unit displays current speaker.
- Multi-User Domains or Dimensions are multi-user text based virtual realities accessible via the Internet which allow people to access the same place at the same time.
- Multi-User Simulation Environment is similar to MUD NTSC.
- Packet Data Network features basic PC applications.
- Plain Old Telephone Service
- Private Virtual Circuit
- Quarter Common Interchange Format
- Regional Bell Operating Company
- Resource Reservation Protocol is a mechanism for reserving bandwidth on the internet so as to provide good performance for real-time audio and video
- DTVC Standards are:
G.7xx - audio codecs
G.723 - speech encoding that specifies a 5.3 kbps standard using Algebraic Codebook Excited Linear Prediction algorithms and a 6.3 kbps rate using Mulitpulse-Maximum Likelihood Quantizer encoding.
H.223 - multiplexing
H.245 - controlling
H.246 - communications control
H.261 - video codecs
H.263 - Quarter Common Interchange Format (QCIF) video coding
H.310 - High Res ATM VTC
H.320 - Narrow-band VTC - digital videoconferencing and ISDN/circuit-switched systems.
H.321 - ATM VTC
H.322 - ISO-Ethernet VTC
H.323 - Ethernet VTC - LAN conferencing gateway/bridge - ethernet and defines standards for terminal, equipment and services for multimedia communications over LANs communicating to systems connected to telephony networks such as ISDN.
H.324 - Low Bitrate VTC - analog-phone videoconferencing with 28.8 kbps as specified in the V.34 standard which would require three pentiums or two P6s.
T.120 - Audio Visual Conferencing Service - collection of protocols and services for data conferencing among many participants via standard phone lines, ISDN and LANs. Backed by Microsoft and Intel.
- Separate Video: separates video into chrominance and luminance components:
chrominance - the difference between a color and a chosen reference color of the same luminous intensity in color television.
luminous - emitting or reflecting flowing light.
- Synchronous is a mode of communication in which participants can communicate simultaneously in real time.
- Virtual Reality Modeling Language) - a language for describing multiparticipant interactive simulations, i.e. virtual worlds networked together via the internet and hyperlinked with the WWW.
- Voice and Telephony Over ATM
- a window or monitor which can be shared between users for writing, drawing and displaying slides, e.g. in postscript format.
Date of last revision: 17 December 2001.
Provided by Mary Kay Demorest.