Kathrein UFD 170 - Manual (Page 78)

Brief Technical Glossary
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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 reverse
compatible, i.e. respond to the analogue switching criteria from
receivers that are only equipped with H/V and 22 kHz control signals.
A DiSEqC™ switching matrix will work with analogue switching critiera
until the DiSEqC™ command from the master is received. All analogue
switching criteria are then ignored.
Dolby Digital
A sound transmission method that allows digital surround sound to be
output on a home cinema system.
DVB-MPEG 2
DVB is the abbreviation for Digital Video Broadcasting. DVB-S refers
to the transmission method (S = satellite). MPEG is the abbreviation
for Moving Picture Experts Group, a working group that formulates
internationally applicable standards for the digital compression of
video and audio. MPEG 2 has established itself as the standard for
compression of digital TV signals. MPEG 2 works up to a data rate of
100 MBit/s.
Eb/No ratio
The Eb/No ratio is a measure of the signal to noise ratio of a digital
signal. The value is not identical to the C/N value familiar from analogue
reception technology. At Eb/No values below 5 dB, reception is
normally no longer possible.
FEC
FEC is the abbreviation for Forward Error Correction. The FEC error
rate corresponds to the Viterbi rate.
PID
The PID (Packet Identifi cation) number is an identifi cation number
for video signals and audio signals in the digital data stream of
DVB-MPEG 2 signals. The receiver uses the PID number to create a
unique assignment for the video and audio data transmission. The
PID PCR is the identifi cation number for the synchronisation signal.
The PID PCR is normally identical to the video PID. For programmes
broadcast in multiple languages, the audio PD can be entered manually
to assign a different language to the TV programme. After the PID is
entered, the digital receiver automatically selects the audio data
identifi ed by the PID number from the data stream and assigns it to the
video signal.