Glossary

ATM

Asynchronous Transfer Mode networks (based on packet switching). A mode of data transfer in which units of data are not time-related to each other.

CODEC

An item of equipment containing an encoder and a decoder. A device which performs the dual function of encoding two-way analogue data and two-way digital data into analogue data.

Echo Canceller

A unit of hardware and software connected to the audio system, used to reduce the amount of echo 'reflected' back to the site transmitting the audio, and thus ensuring adequate sound quality.

EPSRC

Engineering and Physical Sciences Research Council

H.320

A series of audio visual communications recommendations which were ratified by the CCITT in December 1990. The aim of the series, which applies to audio visual communications over 56/64 Kbps to 2.048 Mbps channels, is to ensure videoconferencing systems and video terminals will interconnect across any network. H.320 is an umbrella standard encompassing a series of recommendations

HEI

Higher Education Institute

HEFC

Higher Education Funding Council

ISDN

Integrated Services Digital Network. Basically the existing telephone network using existing but upgraded switches and wiring, but all digital, giving a bandwidth for a basic call of 64 kbps. This increased bandwidth allows the transmission of high fidelity compressed audio, as well as the potential for video communication. Broadband ISDN (ISDN-2, ISDN-6, ISDN-30) is a communication channel having a bandwidth greater than a voice-grade channel 1 and therefore capable of higher-speed data transmission.

JANET

Joint Academic NETwork.

JISC

Joint Information Systems Committee (of the Higher Education Funding Councils of England, Scotland and Wales). Responsible for funding SuperJANET.

Kbps

Kilobits per second

LAN

Local Area Network. A system for intercommunication between computer terminals, PCs and related equipment operating within the same general area.

MAN

Metropolitan Area Network. A geographically extended high-speed LAN designed to interconnect users within a city or metropolitan area.

MBONE

Multicast Backbone. A virtual network that has been in existence since early 1992. Originated from an effort to multicast audio and video from meetings of the IETF. Shares the same physical media as the Internet. MBONE today is used by several hundred researchers for developing protocols and applications for group communication. It is a co-operative, volunteer effort.

Mbps

Megabits per second

MICE

Multimedia Integrated Conferencing for Europe

MCU

Multipoint Control Unit.

SMDS

Switched Multimegabit Data Service.

SuperJANET

A national high performance network supporting UK education and research. It currently provides three services: a high performance IP service to all connected sites, an ATM service to a sub-set of the connected sites and a video network to the ATM sites.

UKERNA

UK Education and Research Networking Association. A company that has been set up to manage the networking programme for the UK higher education and research community

VC

Videoconferencing

VCR

Video Cassette Recorder

WWW

World Wide Web.

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