MAC  Desktop Video Conferencing Terminology  MAC


ADSL
Asymmetrical Digital Service Lines - can transmit at 6.144 megabits but only in a single direction.
Async
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).
BRI
Basic Rate Interface - 3 separate channels: 2B (bearer) and 1D (delta):
    ball 2B - support voice, data and image communications
    ball 1D - carries call set-up and management information.

CSD
Circuit Switched Data is a high speed dial up for data, video, graphics, and images.
CSU
Channel Service Unit
CSV
Circuit Switched Voice for local and long distance voice calls.
CU-SeeMe
A program that provides real time audio and video communication over the internet, available from Cornell University.
DCVC
Desktop Color Video Camera
DSU
Data Service Unit
DVE
Digital Video Everywhere (specific to vendor, InSoft - OpenDVE - VTC solution)
FPS
Frames Per Second:
    ball TV = 30
    ball C-Phone = 30

Hypermedia
A superset of hypertext which combines hypertext and multimedia.
Hypertext
Text containing pointers to other text as cross-references, whereas browsers allow the users to deal with pointers in a transparent way.
IMTC
International Multimedia Teleconferencing Consortium Inc., a non-profit group consisting of 90 conferencing suppliers.
IP-Multicast
Internet Protocol-Multicast is a technique of multicasting on the internet that allows data packets to be passed to multiple selected destinations.
IRC
Internet Realty Chat is a worldwide on-line text-based conferencing system, which allows for multiparty discussions.
ISDN
Integrated Services Digital Network:
    ball Integrated - multiple services supported on one line
    ball Services - voice, data, image, graphics
    ball Digital - faster, more reliable transmission; virtually error free.

ITU
International Telecommunications Union
LEC
Local Exchange Carrier
MBONE
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.
MCP
Multipoint Constant Presence Architecture
MCU
Multipoint Control Unit displays all speakers.
MOO
MUD Object Oriented allows the manipulation and interaction with Cyber-objects in addition to chatting with other people.
MSP
Multipoint Selective Presence Architecture
MCU
Multipoint Control Unit displays current speaker.
MUD
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.
MUSE
Multi-User Simulation Environment is similar to MUD NTSC.
PDN
Packet Data Network features basic PC applications.
POTS
Plain Old Telephone Service
POP
Point-to-Point
PVC
Private Virtual Circuit
QCIF
Quarter Common Interchange Format
RBOC
Regional Bell Operating Company
RSVP
Resource Reservation Protocol is a mechanism for reserving bandwidth on the internet so as to provide good performance for real-time audio and video
Standards
DTVC Standards are:
    ballG.7xx - audio codecs
    ballG.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.
    ballH.223 - multiplexing
    ballH.245 - controlling
    ballH.246 - communications control
    ballH.261 - video codecs
    ballH.263 - Quarter Common Interchange Format (QCIF) video coding
    ballH.310 - High Res ATM VTC
    ballH.320 - Narrow-band VTC - digital videoconferencing and ISDN/circuit-switched systems.
    ballH.321 - ATM VTC
    ballH.322 - ISO-Ethernet VTC
    ballH.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.
    ballH.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.
    ballT.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.

S-Video
Separate Video: separates video into chrominance and luminance components:
    ballchrominance - the difference between a color and a chosen reference color of the same luminous intensity in color television.
    ballluminous - emitting or reflecting flowing light.

Sync
Synchronous is a mode of communication in which participants can communicate simultaneously in real time.
VRML
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.
VTOA
Voice and Telephony Over ATM
Whiteboard
a window or monitor which can be shared between users for writing, drawing and displaying slides, e.g. in postscript format.


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Date of last revision: 17 December 2001.
Provided by Mary Kay Demorest.