| analog |
Currently available radio and television services are
delivered using analog technology, in which the picture, sound and
other information is transmitted as a continuous wave form. |
| ATSC |
The acronym for the US formal standard for digital television.
The Advanced Television Systems Committee [1]
(ATSC), established in 1982, is an international organisation, based
in Washington, DC developing voluntary technical standards for the
entire spectrum of advanced television systems. There are approximately
eighty ATSC member companies and organisations, which represent the
many facets of the television, computer, telephone, and motion picture
industries. |
| datacasting |
Datacasting means the delivery of information (whether
in the form of data, text, speech, images or in any other form) to
persons having equipment appropriate for receiving that information,
using the broadcasting spectrum. |
| digital |
The way in which radio and television services will be
delivered in the near future, as opposed to analog. Digital technology
was first developed for computers, but it is being used for other
communications purposes, such as for telephones and for broadcasting.
Consists of units of information that exist in two states only, on
and off; binary. |
| DTTB |
Digital Terrestrial Television Broadcasting (DTTB) processes
sound and pictures electronically and converts them into a code of
binary digits (`bits'). This code is then transmitted and reconverted
by appropriate receivers into television programs. Digital compression
allows the transmitter to send out only the data needed to pass on
the difference between each picture frame, thus cutting out a lot
of repetitive information associated with analog transmission. The
extent to which compression can be applied depends on the type of
programming and the picture quality required. HDTV (See definition
below) uses a relatively large amount of data and therefore results
in little compression. (Refer below for `terrestrial broadcasting'
definition). |
| DTVR |
Set-top Unit or Digital TV Receiver |
| DVB |
DVB is the acronym for the European formal standard for
digital television, Digital Video Broadcasting. This is a study project
generated by the European Community with the aim of harmonising the
insertion of the new digital audio, TV and other broadcasting systems
in Europe. The DVB project includes over 200 organisations from more
than 25 different countries in all regions of the world. |
| HDTV |
High Definition Television (HDTV) provides cinema like
definition pictures and sound at about twice the resolution of SDTV
(qv). Absolute quality improvement is dependent on program material
quality. |
| hertz |
Cycles per second. Hz = hertz; kHz = kilohertz (1000Hz);
MHz = megahertz (1 million hertz); GHz = gigahertz (1000 million hertz) |
| multi-channelling |
Multi-channelling describes the ability of broadcasters,
due to the emergence of digital technology, to transmit multiple program
streams within the one channel. |
| radio (broadcasting) spectrum |
The term `radio spectrum' describes the subset of frequencies
in the electromagnetic spectrum from 3kHz to 300GHz. Radio spectrum
services include AM radio, FM radio, television and cellular phones.
Australian allocations for TV broadcasting include the 45MHz to 820MHz
band, although some frequencies within this band are used for other
purposes. |
| SDTV |
Standard Definition Television is digital television
with the same format and definitions as the current PAL analog system.
Contrast HDTV above. |
| Simulcast |
Broadcasting the same program on two or more channels
(for example, digital and analog channels) |
| spectrum |
Electric and magnetic fields produce waves that move
through space at different frequencies and the set of all possible
frequencies is called the `electromagnetic spectrum'. This includes
x-rays, cosmic rays, visible light and radio waves. |
| terrestrial broadcasting |
Terrestrial broadcasting involves using land based equipment
(towers and masts), rather than cable or satellite, to broadcast. |