Kathrein UFS 822sw - Manual (Page 147)

147
SHORT TECHNICAL GUIDE
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
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.