Download 9363469a, Operating manual DVB Satellite Receiver UFS

SHORT TECHNICAL GUIDE
CHANNEL PACKAGE
The channel package for a digital transponder normally includes several TV and radio channels. Each
channel package has a fixed 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 downward 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 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 no reception is normally
possible.
FEC
FEC is the abbreviation for “Forward Error Correction”. The FEC error rate corresponds to the Viterbi rate.
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