7 Synchronization
TheFlexiZonePicoIndoorBTSsupportsthefollowingsynchronisationmechanisms:
•
IntegratedGPS/GLONASSreceiver
•
SynchronousEthernet(ITU-TG.8261)
•
TimingoverPacketaccordingtoIEEE1588v2
7.1 GPS / GLONASS
InsteadofusingthetransportnetworkforcarryingthePrimaryReferenceClock(PRC)
traceablesynchronizationreference,itispossibletouseadistributedPRCarchitecture.
Inthiscase,everysiteinthenetworkhasaGPS-basedorothersynchronizationsource
whichprovidesaPRCtraceablesynchronizationreferencesignalforRANNEs.Itisalso
possibletouseacombinationofdistributedandhierarchicalmaster-slavearchitecture.
Insomecases,otherNetworkElements(forexampletransmissionnodes)atthesame
siteprovidethesynchronizationreferenceforRANNetworkElementsthroughexternal
synchronizationinterfaces.
7.1.1 Overall GPS / GLONASS Antenna RF Requirements
Antenna Requirements
TheNokiarecommendedGPS/GLONASSantennasmeetallqualityandfield
performancerequirementsalongwithcriteriaoutlinedinthetablebelowandhaveproven
qualitywithgoodfieldperformance.Whileitispossibletouseotherantennas,
considerablecaremustbeexercisedwhenselectingalternativestoensurefullBTS
compatibilityforallconditions.
Table9
RecommendedGPS/GLONASSAntennaSpecifications
Requirement / Recommendations
Gain +25dB(recommended)
NoiseFigure <2.5dB(recommended)
OperatingFrequency GPS:1575.42MHzwithlessthan3dBattenuationata+1.2MHzoffsetfrom
center(Required)
GLONASS:1602MHzwithlessthan3dBattenuationata+8MHzoffsetfrom
center(Required)
Filtering >40dBattenuationat+50MHzoffsetfromL1center(Recommended))
LNASupplyVoltage Operationwithasupplyvoltageof+4.6VDC+/-0.25V(Required)
LNASupplyCurrent <30mA(Required)
AzimuthCoverage 360°(Required)
ElevationCoverage 10°to90°(Required)
FlexiZoneIndoorPicoBTSProductDescription Synchronization
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