User's Manual
DMR_Manager Operating Manual 2011/07/04 Version 1v2
Reserved Document – Don’t forward without authorization
Page 9 of 51
UHF Link
Circular
TRX
UHF Link
Remote control
AUDIO
Control Center
UHF Link
UHF Link
Circular
TRX
Circular
TRX
UHF Link
Circular
TRX
UHF Link
fc
fc
fc
fc
2/4 Wire
RBS Slave
RBS Slave
RBS Main
fl
fl
fl
fl
UHF Link
RBS Slave
UHF Link
Circular
TRX
fc
RBS Sub-Master
Star simulcast network configuration
2
2
.
.
5
5
D
D
M
M
R
R
(
(
D
D
I
I
G
G
I
I
T
T
A
A
L
L
M
M
O
O
B
B
I
I
L
L
E
E
R
R
A
A
D
D
I
I
O
O
)
)
DMR digital protocol is based upon two TDMA (Time Division Multiple Access) managed timeslots on the same
12.5 KHz wide radio channel. This means that through the same radio channel broadcast by radio network,
two digital communications can be established, and the radio channel capacity is doubled. The use of two
timeslots allows also to exchange control signalling while radio communication is in progress, in order to
manage, for example, the communication priority or to remote control the terminals functionality .
C
H
1
C
H
2
C
H
1
C
H
2
C
H
1
C
H
2
C
H
1
C
H
2
Group 1 Group 2
Time
CH2
Frequency
CH1
7.5KHz
CH4
CH3
7.5KHz
12.5KHz
Two contemporary
and indipendent
communications on
the same frequency
carrier
30ms
A physical radio channel is identified by a couple of frequencies (Duplex and Semiduplex).
Digital modulation requested by DMR standard (4FSK) allows an increased data transmission capacity
compared with analogical traditional systems. In fact the system supports data transmission speed up to 9.6
Kb/s over the 12.5 KHz wide radio channel. It is possible then to implement data services with added value
between terminals and the operative central, like for example radio traffic management and messages,
localization through GPS (Global Positioning System) management, telemetry, with performances greatly
better then what analogical systems can offer