SIST EN 300 462-2-1 V1.2.1:2003

• Abstract:

  For the revision of EN 300 462-2-1. To be put in line with DEN/TM-01080, and also cover activities on network wide synchroniszation, and interaction between SASE and SDH NEs.

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.040.20 - Transmission systems
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Ref Project: ETSI EN 300 462-2-1 V1.2.1 (2002-06) - Transmission and Multiplexing (TM); Generic requirements for synchronization networks; Part 2-1: Synchronization network architecture based on SDH networks

Overview

SIST EN 300 462-2-1 V1.2.1:2003 specifies the generic requirements for designing synchronization network architecture based on Synchronous Digital Hierarchy (SDH) networks. Developed by the Slovenski inštitut za standardizacijo (SIST) in alignment with European standards (EN 300 462-2-1), this document is essential for ensuring precise network-wide synchronization in digital telecommunication systems. The standard addresses both the short-term stability requirements of SDH networks and the long-term stability needs of digital switching networks-such as Public Switched Telephone Networks (PSTN)-that are interconnected with SDH.

This edition revises previous requirements to be consistent with ongoing activities and incorporates best practices for SDH network configuration, network elements (NE), Stand-Alone Synchronization Equipment (SASE), and overall system robustness.

Key Topics

SIST EN 300 462-2-1 V1.2.1:2003 covers several decisive aspects in the domain of telecommunications and synchronization, including:

• Synchronization architecture: Design principles for synchronization network hierarchies tailored to SDH and Plesiochronous Digital Hierarchy (PDH) networks.
• Clock hierarchy: Use and roles of Primary Reference Clock (PRC), Synchronization Supply Unit (SSU), and SDH Equipment Clock (SEC) in providing network-wide accurate timing.
• Distribution methodologies: Approaches for intra-node and inter-node synchronization, including recommended reference chains and topologies (star and tree-like).
• Synchronization modes: Definitions and practical implications of synchronous, pseudo-synchronous, plesiochronous, and asynchronous modes in SDH networks.
• Network robustness: Strategies for enhancing reliability, such as redundant synchronization trails, automatic reconfiguration, and management functionalities.
• Synchronization Status Message (SSM): Mechanisms for quality marking and selection of synchronization trails between network elements.

Applications

The practical value of SIST EN 300 462-2-1 V1.2.1:2003 lies in its guidance for:

• Network operators and designers: Assisting in the planning and deployment of robust synchronization networks that support both legacy and next-generation digital transmission systems.
• SDH/PDH equipment manufacturers: Ensuring that their products align with European synchronization requirements, thereby guaranteeing interoperability and performance.
• Telecom infrastructure development: Facilitating integration between existing networks (PDH) and newer SDH architectures.
• Network management systems: Providing frameworks for configuration, topology management, fault detection, and recovery to maintain service continuity.
• Service providers: Supporting diverse applications like voice, data, and multimedia services that depend on accurate timing and synchronization for reliable delivery.

Related Standards

The requirements specified in SIST EN 300 462-2-1 V1.2.1:2003 are complemented and referenced by several related international standards, including:

• EN 300 462-1-1: Definitions and terminology for synchronization networks.
• EN 300 462-3-1: Jitter and wander control within synchronization networks.
• EN 300 462-4-1: Timing characteristics of slave clocks for SDH/PDH equipment.
• EN 300 462-5-1: Timing characteristics specific to slave clocks in SDH equipment.
• EN 300 462-6-1: Timing specifications for primary reference clocks.
• EN 300 462-7-1: Slave clocks for synchronizing local node applications.
• EN 300 417-6-1: Synchronization layer functions for transport equipment.

These coordinated standards ensure comprehensive coverage of telecommunication synchronization-essential for modern digital transmission and network evolution.

Keywords: synchronization network, SDH, SDH networks, telecommunication synchronization, clock hierarchy, Primary Reference Clock, Synchronization Supply Unit, SDH Equipment Clock, network element, SASE, telecom standards, SIST, EN 300 462-2-1, network architecture.

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Transmission and Multiplexing (TM); Generic requirements for synchronization networks; Part 2-1: Synchronization network architecture based on SDH networks33.040.20Prenosni sistemTransmission systemsICS:Ta slovenski standard je istoveten z:EN 300 462-2-1 Version 1.2.1SIST EN 300 462-2-1 V1.2.1:2003en01-december-2003SIST EN 300 462-2-1 V1.2.1:2003SLOVENSKI
STANDARD
ETSIEN300462-2-1V1.2.1(2002-06)EuropeanStandard(Telecommunicationsseries)TransmissionandMultiplexing(TM);Genericrequirementsforsynchronizationnetworks;Part2-1:SynchronizationnetworkarchitecturebasedonSDHnetworksSIST EN 300 462-2-1 V1.2.1:2003

ETSIETSIEN300462-2-1V1.2.1(2002-06)2ReferenceREN/TM-01092Keywordsarchitecture,SDH,synchronization,transmissionETSI650RoutedesLuciolesF-06921SophiaAntipolisCedex-FRANCETel.:[phone]Fax:[phone]SiretN°34862356200017-NAF742CAssociationàbutnonlucratifenregistréeàlaSous-PréfecturedeGrasse(06)N°7803/88ImportantnoticeIndividualcopiesofthepresentdocumentcanbedownloadedfrom:http://www.etsi.orgThepresentdocumentmaybemadeavailableinmorethanoneelectronicversionorinprint.Inanycaseofexistingorperceiveddifferenceincontentsbetweensuchversions,thereferenceversionisthePortableDocumentFormat(PDF).Incaseofdispute,thereferenceshallbetheprintingonETSIprintersofthePDFversionkeptonaspecificnetworkdrivewithinETSISecretariat.Usersofthepresentdocumentshouldbeawarethatthedocumentmaybesubjecttorevisionorchangeofstatus.InformationonthecurrentstatusofthisandotherETSIdocumentsisavailableathttp://portal.etsi.org/tb/status/status.aspIfyoufinderrorsinthepresentdocument,sendyourcommentto:[e-mail]opartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute2002.Allrightsreserved.DECTTM,PLUGTESTSTMandUMTSTMareTradeMarksofETSIregisteredforthebenefitofitsMembers.TIPHONTMandtheTIPHONlogoareTradeMarkscurrentlybeingregisteredbyETSIforthebenefitofitsMembers.3GPPTMisaTradeMarkofETSIregisteredforthebenefitofitsMembersandofthe3GPPOrganizationalPartners.SIST EN 300 462-2-1 V1.2.1:2003

ETSIETSIEN300462-2-1V1.2.1(2002-06)3ContentsIntellectualPropertyRights.4Foreword.41Scope.62References.63Definitionsandabbreviations.73.1Definitions.73.2Abbreviations.74Synchronizationmethods.75Functionaldescriptionofclocktypes.85.1PrimaryReferenceClock(PRC).85.2SynchronizationSupplyUnit(SSU).85.3SDHEquipmentClock(SEC).96Synchronizationnetworkarchitecture.107Synchronizationmodes.118Synchronizationnetworkreferencechain.129Synchronizationnetworkevolution.149.1SDHnetworks.149.2OpticalTransportNetworks.1410Synchronizationnetworkrobustness.1410.1General.1410.2Trailredundancy.1410.3Synchronizationstatusmessage.1510.4Management.15AnnexA(informative):Bibliography.16History.17SIST EN 300 462-2-1 V1.2.1:2003

ETSIETSIEN300462-2-1V1.2.1(2002-06)4IntellectualPropertyRightsIPRsessentialorpotentiallyessentialtothepresentdocumentmayhavebeendeclaredtoETSI.TheinformationpertainingtotheseessentialIPRs,ifany,ispubliclyavailableforETSImembersandnon-members,andcanbefoundinETSISR000314:"IntellectualPropertyRights(IPRs);Essential,orpotentiallyEssential,IPRsnotifiedtoETSIinrespectofETSIstandards",whichisavailablefromtheETSISecretariat.LatestupdatesareavailableontheETSIWebserver(http://webapp.etsi.org/IPR/home.asp).PursuanttotheETSIIPRPolicy,noinvestigation,includingIPRsearches,hasbeencarriedoutbyETSI.NoguaranteecanbegivenastotheexistenceofotherIPRsnotreferencedinSR000314(ortheupdatesontheETSIWebserver)whichare,ormaybe,ormaybecome,essentialtothepresentdocument.ForewordThisEuropeanStandard(Telecommunicationsseries)hasbeenproducedbyETSITechnicalCommitteeTransmissionandMultiplexing(TM).Thepresentdocumenthasbeenproducedtoproviderequirementsforsynchronizationnetworksthatarecompatiblewiththeperformancerequirementsofdigitalnetworks.Itisoneofafamilyofdocumentscoveringvariousaspectsofsynchronizationnetworks.Thepresentdocumentispart2-1ofamulti-partdeliverablecoveringgenericrequirementsforsynchronizationnetworks,asidentifiedbelow:Part1-1:"Definitionsandterminologyforsynchronizationnetworks";Part2-1:"SynchronizationnetworkarchitecturebasedonSDHnetworks";Part3-1:"Thecontrolofjitterandwanderwithinsynchronizationnetworks";Part4-1:"TimingcharacteristicsofslaveclockssuitableforsynchronizationsupplytoSynchronousDigitalHierarchy(SDH)andPlesiochronousDigitalHierarchy(PDH)equipment";Part4-2:"TimingcharacteristicsofslaveclockssuitableforsynchronizationsupplytoSynchronousDigitalHierarchy(SDH)andPlesiochronousDigitalHierarchy(PDH)equipment;ImplementationConformanceStatement(ICS)proformaspecification";Part5-1:"TimingcharacteristicsofslaveclockssuitableforoperationinSynchronousDigitalHierarchy(SDH)equipment";Part6-1:"Timingcharacteristicsofprimaryreferenceclocks";Part6-2:"Timingcharacteristicsofprimaryreferenceclocks;ImplementationConformanceStatement(ICS)proformaspecification";Part7-1:"Timingcharacteristicsofslaveclockssuitableforsynchronizationsupplytoequipmentinlocalnodeapplications".Part2-1hasbeenrevisedinseveralsectionswithregardtotheworkdoneinEG201793[7]andtoreflectthepresentstatusofsynchronizationnetworks.SIST EN 300 462-2-1 V1.2.1:2003

ETSIETSIEN300462-2-1V1.2.1(2002-06)5NationaltranspositiondatesDateofadoptionofthisEN:31May2002DateoflatestannouncementofthisEN(doa):31August2002DateoflatestpublicationofnewNationalStandardorendorsementofthisEN(dop/e):28February2003DateofwithdrawalofanyconflictingNationalStandard(dow):28February2003SIST EN 300 462-2-1 V1.2.1:2003

ETSIETSIEN300462-2-1V1.2.1(2002-06)61ScopeThepresentdocumentspecifiesthearchitecturalprinciplesthatshouldbeappliedforthedesignofsynchronizationnetworksthataresuitableforthesynchronizationofSynchronousDigitalHierarchy(SDH)andPlesiochronousDigitalHierarchy(PDH)networks.Itsupportstheconstructionofsynchronizationnetworksthatsupportboththeshort-termstabilityrequirementsofSDHnetworksandthelong-termstabilityrequirementsofdigitalswitchingnetworks(e.g.PSTN)connectedtotheSDHnetwork.Itappliestothedesignofnewsynchronizationnetworks.ItdoesnotcharacterizeexistingsynchronizationnetworksbasedonPDHnetworks.Thepresentdocumentspecifiestherulesandarchitecturalprinciplestheimplementationofsynchronizationnetworksshallfollow.ThisinformationissupplementedbyEG201793[7].Itgivesguidanceandexampleshowtheserulesandarchitecturalprinciplescanbeusedtosetupasynchronizationschemeforvariousnetworkconfigurations.2ReferencesThefollowingdocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsofthepresentdocument.• Referencesareeitherspecific(identifiedbydateofpublicationand/oreditionnumberorversionnumber)ornon-specific.• Foraspecificreference,subsequentrevisionsdonotapply.• Foranon-specificreference,thelatestversionapplies.[1]ETSIEN300462-1-1:"TransmissionandMultiplexing(TM);Genericrequirementsforsynchronizationnetworks;Part1-1:Definitionsandterminologyforsynchronizationnetworks".[2]ETSIEN300462-3-1:"TransmissionandMultiplexing(TM);Genericrequirementsforsynchronizationnetworks;Part3-1:Thecontrolofjitterandwanderwithinsynchronizationnetworks".[3]ETSIEN300147:"TransmissionandMultiplexing(TM);SynchronousDigitalHierarchy(SDH);Multiplexingstructure".[4]ETSIEN300462-5-1:"TransmissionandMultiplexing(TM);Genericrequirementsforsynchronizationnetworks;Part5-1:TimingcharacteristicsofslaveclockssuitableforoperationinSynchronousDigitalHierarchy(SDH)equipment".[5]ETSIEN300462-6-1:"TransmissionandMultiplexing(TM);Genericrequirementsforsynchronizationnetworks;Part6-1:Timingcharacteristicsofprimaryreferenceclocks".[6]ETSIEN300462-4-1:"TransmissionandMultiplexing(TM);Genericrequirementsforsynchronizationnetworks;Part4-1:TimingcharacteristicsofslaveclockssuitableforsynchronizationsupplytoSynchronousDigitalHierarchy(SDH)andPlesiochronousDigitalHierarchy(PDH)equipment".[7]ETSIEG201793:"TransmissionandMultiplexing(TM);Synchronizationnetworkengineering".[8]ETSIEN300462-7-1:"TransmissionandMultiplexing(TM);Genericrequirementsforsynchronizationnetworks;Part7-1:Timingcharacteristicsofslaveclockssuitableforsynchronizationsupplytoequipmentinlocalnodeapplications".[9]ETSIEN300417-6-1:"TransmissionandMultiplexing(TM);Genericrequirementsoftransportfunctionalityofequipment;Part6-1:Synchronizationlayerfunctions".SIST EN 300 462-2-1 V1.2.1:2003

ETSIETSIEN300462-2-1V1.2.1(2002-06)73Definitionsandabbreviations3.1DefinitionsForthepurposesofthepresentdocument,thetermsanddefinitionsgiveninEN300462-1-1[1]apply.3.2AbbreviationsForthepurposesofthepresentdocument,theabbreviationsdefinedinEN300462-1-1[1]andthefollowingapply:ADMAddDropMultiplexerAISAlarmIndicationSignalNENetworkElementOTNOpticalTransportNetworkPDHPlesiochronousDigitalHierarchyppmpartspermillionPRCPrimaryReferenceClockPSTNPublicSwitchedTelephoneNetworkSASEStand-AloneSynchronizationEquipmentSDHSynchronousDigitalHierarchySECSDHEquipmentClockSETGSDHEquipmentTimingGeneratorSETSSDHEquipmentTimingSourceSSUSynchronizationSupplyUnitSSMSynchronizationStatusMessageSTM-NSynchronousTransportModuleN4SynchronizationmethodsMaster-slavesynchronizationisappropriateforsynchronizingSDHnetworksandthefollowingmaterialoffersguidanceonusingthismethod.Master-slavesynchronizationusesahierarchyofclocksinwhicheachlevelofthehierarchyissynchronizedwithreferencetoahigherlevel.Therearefourqualitiesofclockinthesynchronizationhierarchyshownbelow:-PrimaryReferenceClock(PRC):seeEN300462-6-1[5];-slaveclock(transitnode):seeEN300462-4-1[6];-slaveclock(localnode):seeEN300462-7-1[8];-SDHEquipmentClock(SEC):seeEN300462-5-1[4].ThePRCisthehighestqualityhierarchicalclockandtheSECisthelowestqualityclock.Higherqualityclocksshallnotbesynchronizedbylowerqualityclocksinholdovermode,butclocksinholdovermodecanbeusedtosynchronizeclocksofthesamequality.Therearelimitsonthenumberofclocks,whichcanbeconnectedinasynchronizationdistributiontrail(seeclause8).Clockreferencesignalsaredistributedbetweenlevelsofthehierarchyviaadistributionnetwork,whichmayusethefacilitiesofthetransportnetwork.ThetransportnetworkmaycontainSECs.Thedistributionoftimingbetweenhierarchicalnodeclocksshallbeperformedusingamethod,whichavoidsintermediatepointerprocessing.Twopossiblemethodsareasfollows:a)recovertimingfromareceivedSynchronousTransportModuleN(STM-N)signal(thisavoidstheunpredictableeffectofapointeradjustmentonthedownstreamslaveclock);b)derivetimingfromasynchronizationtrailthatisnotsupportedbyaSDHnetwork.Themaster-slavemethodusesasingle-endedsynchronizationtechniquewiththeslaveclockselectingthesynchronizationtrailtobeusedasitsreferenceandchangingtoanalternativeiftheoriginaltrailfails.Thisisaunilateralcontrolscheme.SIST EN 300 462-2-1 V1.2.1:2003

ETSIETSIEN300462-2-1V1.2.1(2002-06)85Functionaldescriptionofclocktypes5.1PrimaryReferenceClock(PRC)ThePRCisalogicalfunctionconformingtotherequirementsofEN300462-6-1[5].Itgeneratesthemasterclockforanetworkorpartofanetwork.ThePRCequipmentmayeither:-implementitsownfreerunningoscillator(e.g.Caesiumtubeoscillator);or-beaslaveclockbeingsynchronizedtoahighaccuracyfreerunningclockbyterrestrialorsatelliteradiosignals(e.g.GPS).5.2SynchronizationSupplyUnit(SSU)ASSUisalogicalfunctionconformingtotherequirementsofEN300462-4-1[6]orEN300462-7-1[8].It:-acceptssynchronizationinputsfromanumberofsources;-selectsoneoftheseinputs;-f
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