83
Short Technical Glossary
AC 3
Output for Dolby Digital signal
ASTRA
SES (Société Européene des Satellites) satellite
system. Analogue and digital transponders in the
frequency range 10.7-12.75 GHz.
AV programme pos.
Preferred programme slot on TV set for external
connections such as Scart and HDMI
CAM – Conditional Access Module
Decryption decoder, which uses a Smartcard to
decrypt the encrypted radio and TV signals.
Channel package
The channel package for a digital transponder
normally includes several TV and radio channels.
Each channel package has a
fi
xed assignment
for the transponder transmission frequency, for
polarisation (horizontal or vertical), for the symbol
rate and for the Viterbi rate or error rate.
CI – Common Interface
Internationally standardised interface for CA
modules
Composite colour video signal
Colour baseband signal for the transmission of
colour video signals
Data rate
Data bits transmitted per second. Is expressed in
kbit/s or Mbit/s. The higher the data rate the better
the quality of the transmitted signal.
Data reduction
Compression of video and audio signals. Redundant
information is discarded.
DiSEqC™
DiSEqC™ (Digital Satellite Equipment Control) is a
communication system between a satellite receiver
(master) and the peripheral satellite components
(slaves), such as LNBs, multi-switches, rotating
antenna systems.
It is a single master/multi-slave system, i.e. there
is only ever one master in the satellite system. All
activities start from the master.
DiSEqC™ components
If DiSEqC™ switching matrices are cascaded,
the master receiver must transmit the DiSEqC™
signal several times, so that all DiSEqC™ multi-
switches in the cascade receive their commands.
These days, DiSEqC™ components (slaves) must
be downwards compatible, i.e. respond to the
analogue switching criteria from receivers that are
equipped only with H/V and 22 kHz control signals.
A DiSEqC™ switching matrix will work with
analogue switching criteria until the DiSEqC™
command from the master is received. All analogue
switching criteria are then ignored.
Dolby Digital 5.1
Dolby Digital is a sound transmission that allows
digital surround sound to be output on a home
cinema system.
DVB – Digital Video Broadcasting
DVB-S refers to the transmission method
(S = satellite, C = cable, T = terrestrial).
DVB-S2
An enhanced DVB-S signal for HDTV with better
quality.
EUTELSAT
European Satellite operator, based in Paris.
Many orbit positions and European customers.
Transponders in the frequency range 10.7-
12.75 GHz.
FAT and FAT32
File systems for storage media
FEC
FEC is the abbreviation for “Forward Error
Correction”. A technique for reducing the error rate
of data transmission. Additional bits are inserted
into the data stream, so that error-correction
algorithms can be used on reception. The FEC
error rate corresponds to the Viterbi rate.
GNU
GNU is not Unix, it is an open operating system
for software developers.
HD – Ready
This is a label created by the EICTA (European
Information, Communications and Consumer
Electronics Industry Technology Association) for
equipment that is capable of reproducing HDTV.