User's Manual Part 1

Connecting a Main Hub to a Base Station
InterReach Fusion Wideband Installation, Operation, and Reference Manual Page 103
D-620616-0-20 Rev H • TECP-77-044 Issue 7 • May 2013 © 2013 TE Connectivity Ltd.
Figure20.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anRAUband.Forinstance,thiscouldbeforan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Attenuat
ion:Theuplinkattenuatorattenuatesenvironmentalnoisepickedupbyan
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an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