SHORT TECHNICAL GUIDE
CHANNEL PACKAGE
The channel package for a digital transponder normally includes several TV and radio
programmes. 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.
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 criteria until the DiSEqC™
command from the master is received. All analogue switching criteria are then ignored.
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 MB/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 no reception is normally possible.
FEC
FEC is the abbreviation for "Forward Error Correction". The FEC error rate corresponds to the
Viterbi rate.
OTR
One Touch Recording
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