SyncEprovidesahighqualitysynchronizationreferenceforbasestations,comparableto
SDHsynchronization.Thestabilityoftherecoveredfrequencyisindependentofthe
networkloadornetworkimpairmentslikedelayvariations.
Aco-locatedoranotherchainedtailsitecanbesynchronizedwithSynchronousEthernet
generationusingSyncE.
BothBTSSynchronousEthernetandTimingoverPacketfeaturescanbeactivated
simultaneously.Thefeaturescanbesetindividuallyasprimaryandsecondary
synchronizationsources.WhenbothSyncEandIEEE1588ToParefeasibleinthe
priorityconfiguration,theselectionofToPorSyncEasprimaryorsecondaryreferences
isakeypointinthedesignofthesynchronizationnetworkanddependsverymuchon
thecharacteristicsofthemobilebackhaulnetworkbeingusedtoaccesstheBTS.
Inaddition,whenSynchronousEthernetGenerationfeatureisactivated,bothSyncEand
TimingoverPacketcanserveasaninputforgeneratingSyncEsignaltowards
chained/collocatedBTS.
7.3 Timing over Packet
TimingoverPacket(ToP)canbealsoconsideredasanexampleofmaster-slave
architecture.TheToPmastersendstimingpacketstoToPslaves.ToPslavesrecoverthe
timingreferencefromthereceivedtimingpackets.
ThetransportnetworkbetweentheToPMasterandtheToPSlaveembeddedintheBTS
mustfulfillcertainengineeringrulestoguaranteeproperoperationofToPas
synchronizationsourcesuchthatthestabilityofthefrequencyfortheairinterfacemeets
3GPPrequirements(+/-50ppb).Theseengineeringrulesarerelatedtothetreatmentof
theIEEE1588ToPpacketsinthenetworkandSLAvaluesforPacketLossandPacket
DelayVariation.
Synchronization FlexiZoneIndoorPicoBTSProductDescription
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