User's Manual Part 1

Connecting a Main Hub to a Base Station
InterReach Fusion Wideband Installation, Operation, and Reference Manual Page 101
D-620616-0-20 Rev H • TECP-77-044 Issue 7 • May 2013 © 2013 TE Connectivity Ltd.
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.F
or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
basestation,thefollowing
equipmentmayberequired:
• ci
rculators
• filterdipl
exers
• dir
ectionalcouplers
• combiner/splitters
• attenuators
• coaxcables
• connectors.
Inaddition,usethefollowingconsiderationstoachieveoptimalpe
rformance:
• 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Section6.3,
“MaximumOutputPowerperCarrier,”onpage6‐4.
• Theuplinkatten
uationshould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
Main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.