Radwin 2000 - Chapter 14: Using the RADWIN GSU; What Is It for; GSU Functionality; Typical GSU Scenarios

RADWIN2000UserManual Release2.8.30 14‐1
Chapter14:
Usingthe RADWINGSU
Whatisitfor
TheGPS‐basedsynchronizationunit(GSU)isdesignedtohandleinter‐siteinterferences
underlarge‐scaledeploymentscenarios.
TheGSUisanoutdoorunitconsistingofasmallsizeenclosure,aGPSantennaandaPoE
device.
TheGSUisconnectedtotheHSSUnitusingastandardHSScable.Itsynchronizesthe
transmissiontimingofmultipleHub‐Sitestothe sameclocksourcethuseliminatingmutual
inte rference.
GSUFunctionality
TheGSUreceivesasynchronizationsignalfromtheGPSoncepersecond.Itdistributesa
RADWINproprietarysynchronizationsignaltoallotherODUunitsusingtheRS422protocol
andthestandardHSSmechanism,wheretheGSUactsasanHSMunit.
WhentheGSUdoesn’treceiveasynchronizationsignalfromtheGPSfor30seconds,itmoves
automaticallytoSelf‐GenerationmodeandactsasaregularHSMunit,untiltheGPSrecovers.
TypicalGSUScenarios
IndependentDistributedSites
InthescenarioofFigure14‐1,wehavemultipleindependentcollocatedsites,whichmay
inte rferewitheachother.Tomeetthissituation,wecoordinateallofthemusingtheGSUas
shown.
TheGSUfunctionslike“wideareaHSSunit”,ensuringthatallparticipatingradiosatthe 
locationsmarkedGSUeachtransmitandreceiveatthesametime.