Kathrein UFS 702sw - Manual (Page 63)

63
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 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.