User Manual

OPTICAL MASTER UNIT
PRODUCT DESCRIPTION AND USER’S MANUAL
© Axell Wireless Ltd 27
3.6.1.1.2 Fiber Loss Compensation
Activate the fibre loss compensation in both the downlink (from the OMU) and in the uplink (from
the repeaters) paths. See
3.7 Initiate Fiber Loss Compensation.
3.6.1.1.3 Uplink Path
The uplink gain setting of the OMU and connected repeaters affects the sensitivity in the connected
BTS sector and the connected repeater cells. The recommended method for setting up the system
below will give good noise performance in simple systems with a relative low number (less than six)
of connected repeaters per BTS sector.
For more complex systems, with many repeaters connected to the same BTS sector using multi-drop,
a more detailed system analysis is required to set up the system in an optimum way.
• Set the uplink attenuation in the OMU equal to the downlink attenuation.
• Set the uplink gain of each connected repeater equal to the downlink gain of the repeater (by
setting the attenuation value in the RMC for both links equal).
Select “HUB Status”
Seet the attenuation
in the uplink in this
box.
3.6.1.1.4 Noise Considerations
To reduce the noise degradation of the base station, it is recommended to reduce repeater uplink gain
only. The repeater cells will in this case not be perfectly balanced, i.e. downlink can take higher path
loss than uplink. In typical systems where you want to cover for example a road tunnel by tapping off
a BTS nearby this small imbalance is less of a problem.
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See section 3.3 Fiber Loss Compensation for information about this feature.
Start with the
OMU
Chose “Actions/Perform Optical Loss Adjustment” from the drop down
menu.