User Manual

Optical Master Unit
PRODUCT DESCRIPTION AND USER’S MANUAL
© Axell Wireless Ltd A1829300 rev H 24 (86)
Alternative 2
The OMU and the wireless modem operate on different bands
(for example an OMU for TETRA with a GSM modem)
In this case the OMU will have one port where an external
antenna can be connected.
The connector is SMA type.
Modem
ANT
To external
antenna
2.3 Block Diagram
An OMU can be configured in many different ways. These are two examples.
Example 1
In this example the OMU is fed from the back so the links on the UL Combiner and the DL Splitter units are
mounted.
There is a duplex filter and therefore a combined RF in/out.
The wireless modem, which is placed on the Control Module, is connected to the coupler in the filter via the
Modem Antenna Connection Module.
RF Backplane
Opto Module
RF
IN
RF
OUT
Control Module
External Alarm and Battery Module
Rack Com Board
Power Module B
Power Module A
Digital Backplane
RF in/out
Duplex Filter
DL Splitter
UL Combiner
Opto Module
RF
IN
RF
OUT
Opto Module
RF
IN
RF
OUT
Opto Module Opto Module
RF
IN
RF
OUT
Opto Module
RF
IN
RF
OUT
Opto Module
RF
IN
RF
OUT
To coupler for
modem antenna