Intempo Digital PG-01 Instruction Manual page 12

Glossary
DAB
Ensemble/Multiplex
MULTIPLEX
PRIMARY SERVICES
(STATIONS)
Service
Bit rate
RDS
FM
Stands for Digital Audio Broadcasting. Analogue
radio is transmitted by placing the audio onto a
carrier. If there is any interference or static with
the wanted signal then it will be heard on the
receiver's speaker. Digital however is transmitted
in the form of a digital stream. The decoder in the
radio knows what data is needed to re-construct
the original signal, so any other unwanted signal
is discarded.
Unlike analogue systems, digital radio groups
together separate signals from a number of
stations and transmits them as a complete,
interleaved data stream. This is known as an
Ensemble or Multiplex.
Up to ten digital services can be transmitted in a
single multiplex. This allows several programmes
or services to be transmitted on a single frequency.
Radio stations e.g. Radio 1 are known as services
when talking about DAB transmissions.
In simple terms when talking about music the
higher the bit rate is the better the sound quality
will be. For near CD quality audio128Kbps (kilo
bits per second) will suffice. So stations that are
continually playing music etc use 128Kbps.
Stations that generally only transmit speech etc.
such as news stations can use 64Kbps as
speech doesn't require such a high bit rate.
Radio data system. The broadcaster can include
data with their transmission. This data can then be
displayed on the user receiver in a scrolling text
format. The Data can include information such as
station name and traffic announcements etc.
Frequency modulation