【 Weak current College 】 audio, video introduction to the field of common terminology---Power By 【 China power house network 】

CCITT: now for ITU-T. Part of the Alliance, which is the dominant telecom main standards.

CCITT compatible codec solution for decoders: video decoder is H.320 series standard minimum requirement in the statement. Different manufacturers of systems for video conferencing needs it.

President control: a video switching mode (use ITU-T specification video Exchange H.243 standard). In this way, a conference site from meeting system controller, select the current broadcasters. The meeting must use voice activated video switching (i.e. video selection) and install ITU-T specification H.243 seated control choices. It and the user to select contrast video Exchange.

Channel: 1. one of the smallest subdivision of the loop. It provides a single type of communication services.
2. two or more Terminal transmission paths.
CIF universal media formats: standard for H.261 video frames. This frame is 288 352 pixels, the maximum speed of 30 frames per second.
Series solution of decoders: coder-decoder. A device that is compiled into the analog signal used to transmit digital signals, the digital signal to analog signal translation solution for receiving.

Split-screen: a way to allow each participants also saw several people's technology. ----Usually can reach four--just to see the current speaker.

Data Conference: video conferencing in the same person can collaborative action document. Sharing such as electronic files, remote testing. Share a video clip is possible. Data meeting the Conference of the potential advantages, are important business tools.

MCS: multimedia conferencing services. A device cannot link three or more places and fully interactive multi-site video conferencing

MPEG: dynamic picture experts group. ISO dynamic audio video compression standard.

NTSC: national television standards Committee. Typically used to specify the North America and Japan for color TV system standards.

PAL: phase alternating line. Universal standard for the European radio and television.


Asynchronous: non-synchronized. A data transmission mode, in the beginning of a character with a start bit, stop bit at the end of use. The time interval between characters may be different. In the video, when its timer and system reference signal timing, it signals is asynchronous.

Asynchronous transfer: a single character in irregular intervals, each consists of a start bit, stop bit end begins.

ATM: asynchronous transfer mode (also for cell relay). ATM provides a single network interface to the audio, video, images and text to accommodate these different types of media. ATM transmission technology using multiplexing techniques, it put the data into a small fixed-length cells is called a cell. Each cell contains a 48-bit information field and 5 bits of the header information.

Broadband: a channel host information.

BasicRateISDN: from 2 64Kb ' B ' channel and 1 16Kb ' D ' channel of ISDN lines of the most basic form. Approximately two analog telephone line. BRI also made.

B-channel: BRI three channel in two used to transmit information.

D-channel: BRI three channel, is designated for control and signal on the ISDN.

BER: measuring the quality of digital telecommunications networks. A 10-6 of BER, or an error in million, is a typical digital telecommunications system.

B-ISDN broadband ISDN: ITU-T B-ISDN standards under development, combined with the existing ISDN switching, signaling, multiplexing and transmission standards become a higher standard that supports different types of information in the public switched network.

Bongding: bandwidth required cooperative organizations. The more than 30 merchants Union to reverse multiplexer developed the standard. In 1992 by the 1.0 version describes the different manufacturers of reverse multiplexer four modes, how a broadband signal into 56Kb/s or 64Kb/s channel, how these private channel crossing Exchange digital network and how to reorganize them at the receiving end to a single high-speed signal.

Basic rate interface BRI: see BasicRateISDN

Bridge: a signal from one network loops across another electronic device. In the video TV, network bridge is the abbreviation for multipoint bridge, it enables three or more meetings sites connected together, so that they can at the same address. Multipoint bridge is usually for MCS: multipoint Conferencing Server. In IEEE802 specifications, network bridge is to extend LAN physical environment to the OSI model of data link layer in LAN or LAN segment connected devices. They work in the data frame, in the network and send them. They record the site address, and participate in the spanning tree algorithm uses topology loops to solve the problem. Finally, when the bridge is used for audio conferencing, it refers to the number of voice calls connected devices so that the meeting can hear and be heard.

Private network: telecommunication network, specialized leasing network provides direct site (personal) connection.

E1: 2.04mb European data transmission standard.

Echo cancellation: a way to prevent echo during the meeting of equipment

Terminal: a Terminal site

Gatekeepers: the H.323-based IP network devices, control network or between the flow of information across a network. It can allocate bandwidth that allows special service or user preference.
R > gateway: two different network connection through a combination of hardware/software. H.323-H.320 gateway to connect to a LAN, ISDN terminal to Terminal. Gateway to control network traffic and provides addresses and the Protocol to transmit.

Synergy: the device is fully compatible with the special nature and ability to work together. When coming from different manufacturer's code for supporting different maximum performance and mixed, this is mainly to consider.

ISDN: integrated services digital network

ISO: international standards organizations

JPEG: Joint Photographic Experts Group. ISO image compression standard

LAN LAN: a local area network LAN. Usually in small area such as a building or a company in connection to the computer.


POTS: pots (plain) phone service, also is a regular phone line.

PRI primary rate interface: high-performance, ISDN line, consisting of 23 B-channels and one D-channel.

PSTN: public switched telephone network

RJ-45: ISDN standard slots, as well as 1808877

T.120: management instant data conference ITU-T standards. It supports all current standards of commercial agreements including telephone line, ISDN, PSDN, CSDN and LAN protocols.

T1: 1.544Mb/s transfer rate of the United States figures. Similar European E1.

TerminalAdapter terminal adapter used to connect ISDN. It is like a telephone network modems.

WAN Wan: wide area network WAN is, in a broader context for example, a town or a city connected to your computer. It can also be a number of local area network.

X.21: telecommunication interface standard