User's Manual Part 1

SystemDescription
34
Repeaters
BirdTechnologiesoffersawidevarietyofrepeaterstoboostoffairsignals.Therepeatedsignalscanfeedpassive
DASorcanbeusedasaninputintotheactiveDAS.
DMR 400 Series Rack Mount Repeater
TheDMR400isdesignedtofitintheHeadendMasterFramealong withtheBIUandFOIcards.Thesystemwas
originallydesignedtobeusedinmovingcoverageareassuchasshipsandtrainsthatrequireactivecontroloverthe
downlinkgain(linksymmetry)tocompensateforwidevariationsintheoff‐air
signals,butthesystemcaneasilybe
implementedintraditionalfixedlocationssuchasofficesandhospitals.
Figure 23 DMR 400 Rack Mount Repeater
AlthoughtheDMRrepeatersarerackmountedwiththeactiveDAScomponents,theDMRrepeatercanfunctionas
astandaloneunittoprovidecoveragetoapassiveDAS.
TheDMRre
peaterfamilyofferslinksymmetrysettings.Thisfunctionisusedtoautomaticallyadjusttheuplinkgain
basedonthedownlinksignal.Wheninstalledinmovingcoverageareassuchastrains,thefeaturepreventsthe
repeaterfromdesensitizingthedonorsitebyautomaticallycontrollinguplinklevels.
TheDM
Rre
peateralsooffersself‐oscillationprotection.Thisfunctionisusedtodetectproblemswithisolation
betweenthedonorandserviceantenna.Therepeaterwillinterveneandlowerthegaintoalevelequaltothe
isolationminusthestabilitymargin.ThesettingsareseparateforULandDL.
 On/Off
 Stabilitymargin:Valuesettingofhowmuchlowerthegainshouldbethanthecalculatedisol ation.Rangeof
0.0to20.0dBm.
 Recoverytime:Timethatshouldpassbeforetherepeaterresetthegaintothevaluespecifiedlevelin“RF
Config”(setgain).Rangeof30to86,400seconds.
 Recoverymargin:Setvalueofgainlevelabovethegainspecifiedin“RFConfig”(setgain)thatisusedwhen
therepeaterrecoversafterthe“RecoveryTime”.Rangeof0.0to20.0dBm.
TheDMR400of
fersvariablebandwidthsupto35Mhz,dependingontheconfiguration.
Remoteaccessca
nbeprovidedviaanEthernetconnectionorthroughtheBirdRemoteGateway.SNMPisa
standardontheunits.Noproprietarysoftwareisrequired.Operationalparametersaresetviaawebbrowser.