User's Manual

Connecting a Main Hub to a Base Station
InterReach Fusion Wideband Installation, Operation, and Reference Manual Page 103
D-620616-0-20 Rev K • TECP-77-044 Issue 9 • March 2015 © 2015 TE Connectivity
Figure 16. ALC Operation
Using the RAU 10 dB Attenuation Setting
Each RAU band can, independently of the other RAUs in a system, have its uplink or downlink gain
attenuated by 0 or 10 dB for each RAU band (1, 2 or 3). This is accomplished by selecting the
appropriate UPLINK and/or DOWNLINK attenuation for each RAU band in the Edit Unit Properties
screen of AdminBrowser for the selected RAU.
• Downlink Attenuation:
The downlink attenuator provides a mechanism to reduce the signal
strength from a RAU band. For instance, this could be for a RAU band located near a window
in a tall building that is causing excessive leakage to the macro-network. In such a case it is
important to attenuate the downlink only. The uplink should not be attenuated. If the uplink
is attenuated, the uplink sensitivity is reduced and mobile phones in the area of that RAU band
will have to transmit at a higher power. This would increase interference to the outdoor
network from such mobiles.
• Uplink Attenuation: The uplink atte
nuator attenuates environmental noise picked up by a
RAU band located in an area where heavy electrical machinery is operating. In such
environments the electrical noise can be quite high and it is useful to reduce the amount of
such noise that gets propagated through the distributed antenna system. Attenuating the
uplink of a RAU band located in areas of high electrical noise helps preserve the sensitivity of
the rest of the system.
Attack
Phase
Release
Phase
Hold
Phase
Output Signal
Level
Activation
Level
-30 dBm
Input Signal
Level
Release
Level
-45 dBm
Time
1
1
5
2
3