User's Manual

Connecting a Main Hub to a Base Station
InterReach Fusion Wideband Installation, Operation, and Reference Manual Page 101
D-620616-0-20 Rev K • TECP-77-044 Issue 9 • March 2015 © 2015 TE Connectivity
CONNECTING A MAIN HUB TO A BASE STATION
The Fusion Wideband system supports up to three RF sources: one for Band 1, one for Band 2 and
one for Band 3. This section explains how each band can be connected to its associated Base
Station.
Each Fusion Main Hub band has separate system gain parameters. Fo
r example, Band 1 can be set
for +5 dB of downlink system gain while Band 2 can have +15 dB of downlink system gain. Thus,
each band can be configured as a separate system to allow for full integration to its associated
Base Station.
When connecting each of the Fusion Wideband Main Hub bands to its B
ase Station, the following
equipment may be required:
• circulators
• filter diple
xers
• directional couplers
• combiner/splitters
• attenuators
• coax cables
• connectors.
In addition, use the following considerations to achieve optimal pe
rf
ormance:
• The downlink power from the Base Stations must be attenuated enough so that the power
radiated by
the RAU does not exceed the maximum Power Per Carrier listed in “Maximum
Output Power Per Carrier” on page 65.
• The uplink attenuation sho
uld be small enough that the sensitivity of the overall system is
limited by Fusion Wideband, not by the attenuator. However, some Base Stations trigger
alarms if the noise or signal levels are too high. In this case the attenuation must be large
enough to prevent this from happening.
CAUTION! The UPLINK and DOWNLINK ports cannot handle a DC power feed from a BTS. If DC power is
present, a DC block must be used or the Fusion Wideband Main Hub may be damaged.
If, in an area covered by Fusion Wideband, a mobile phone indicates good signal strength but
consistently has difficulty completing calls, it is possible that the attenuation between Fusion
Wideband and the Base Station needs to be adjusted. In other words, it is possible that if the
uplink is over-attenuated, the downlink power will provide good coverage, but the uplink
coverage distance will be small.
When there is an excessive amount of loss between the Fusion Wideband M
ain Hub uplink and its
associated band’s Base Station, the uplink system gain can be increased to as much as 15 dB to
prevent a reduction in the overall system sensitivity.