User's Manual

DMR repeater 24/01/2011 Versione 1.1
Documento Riservato - non divulgabile senza autorizzazione
Pag. 8 / 55
In this way all satellites are zeroed in frequency compared to master and then zeroed between them.
If there is not a good frequency synchronization the quality of communication considerably decreases in the
equal fields strenght areas.
Another essential function of
R
RR
R
R
RR
R
a
aa
a
a
aa
a
d
dd
d
d
dd
d
i
ii
i
i
ii
i
o
oo
o
o
oo
o
A
AA
A
A
AA
A
c
cc
c
c
cc
c
t
tt
t
t
tt
t
i
ii
i
i
ii
i
v
vv
v
v
vv
v
i
ii
i
i
ii
i
t
tt
t
t
tt
t
y
yy
y
y
yy
y simulcast networks is the voting, which is the method by which
the best signal received from the network is continuously selected. The signal voted is sent to the satellite and
then diffused in the whole coverage area.
Simulcast networks require also particular attention in the choice of media linking the various stations. The
characteristics of these media must be such as to make as much as possible identical signs of low frequency
(audio) that each station must retransmit.
For that reason simulcast networks made by
R
RR
R
R
RR
R
a
aa
a
a
aa
a
d
dd
d
d
dd
d
i
ii
i
i
ii
i
o
oo
o
o
oo
o
A
AA
A
A
AA
A
c
cc
c
c
cc
c
t
tt
t
t
tt
t
i
ii
i
i
ii
i
v
vv
v
v
vv
v
i
ii
i
i
ii
i
t
tt
t
t
tt
t
y
yy
y
y
yy
y employ equalization devices based on Digital
Signal Processing, which are able to automatically minimize the differences between the media paths
This feature allows to use a large family of communication media, including time-varying lines as pupinized
copper, presenting considerable variations in temperature, or as non-dedicated telephone lines and therefore
subjected to variations of delay and BF response.
.
TRX
VHF
TRX
VHF
TRX
VHF
RF broad.
Km_2
RF broad.
Km_1
RF broad.
Km_0
MUX_1
delay
MUX_2
delay
SLAVE2
SLAVE1
MASTER
Linear simulcast network configuration