10G EPON- Unleashing the Bandwidth Potential · PDF fileZTE actively participates in various...
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10G EPON- Unleashing the Bandwidth Potential
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Product Type Technical DescriptionVersion Date Author ApprovedBy Remarks
V1.00 �00�-0�-�4SameerAshfaqMalik
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©�00�ZTECorporation.Allrightsreserved.ZTECONFIDENTIAL:ThisdocumentcontainsproprietaryinformationofZTEandisnottobedisclosedorusedwithoutthepriorwrittenpermissionofZTE.DuetoupdateandimprovementofZTEproductsandtechnologies,informationinthisdocumentissubjectedtochangewithoutnotice.
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Content TABLE OF CONTENTS1 Abstract………………………………………………………………………………………1
2 Introduction…………………………………………………………………………………1
3 IEEE 802.3av 10Gbit/s Ethernet-based PON (10G EPON) ……………………………2
4 Standardization Timeline…………………………………………………………………3
4.110GEPONCo-existencewith1GEPON…………………………………………………4
5 Power Budget………………………………………………………………………………5
6 10G EPON Optical Spectrum Allocation…………………………………………………6
7 Forward Error Correction (FEC)…………………………………………………………6
8 Dynamic Bandwidth Allocation (DBA)…………………………………………………6
9 10G Convergence……………………………………………………………………………7
10 10G EPON Industrial Chain………………………………………………………………7
11 Conclusion……………………………………………………………………………………8
FIGURESFigure110GEPONprotocolstack……………………………………………………………�
Figure�showsthe10GEPONprotocolschedule.……………………………………………�
Figure�10Gand1GEPONco-existence……………………………………………………4
Figure410GEPONWavelengthAllocationChart……………………………………………6
Figure5Convergencesat10G…………………………………………………………………7
TABLESTable1MajorMilestones in10GEPONStudyGroup………………………………………�
Table�PowerBudgetExplanation………………………………………………………………5
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1 AbstractFor thefirst time inhistory,wecannowaimto live in“OneWorld”,becausethe�1stcenturyhasushered inanewera inman’songoingquest forabetter lifeandabetterworld.Telcoindustry ispassing throughaphaseofmultiservice revolution,withashift from legacy tonextgenerationnetworksandtheintroductionofnewandadvancedservices(e.g.�DTV,HDTV,IPTV,VoIP,WiMAX,MobileTV,etc.).Moreandmoreserviceprovidersareprogressingtotriple-playandevenquad-playpackagesinordertoprovideaone-stopshoppingservicetocustomers. IPtrafficisgrowingexponentiallyandnetworksevolveto includebandwidthhungryIP-basedapplicationsonvoice,videoanddata.Adiscussionaboutbroadbandmediumandspeed isoneveryone’stongue.Butstillitisunderdiscussionthat“how fast is fast enough”.Infact,broadbandisnotjustaspeeditisdefinedasapotentialmediumthatoffersawidevarietyofapplicationstousersattheirpremises.ThiswhitepaperprovidesadetailedtutorialoverviewoftheIEEE 802.3av 10Gbit/s Ethernet PON (10G EPON)market trends thataredriving therequirementof future lastmileaccessnetworks,standardizationadvancements,technologyinfrastructure.
2 IntroductionTheusers thirst forhighercapacity,versatilediversityandmorepersonalizationofservices iskeeponincreasingatrapidpace.Videoandbandwidthhungryapplicationsdrivetherequirementsforversatileaccessnetworkandfiber to the lastmile.Opticalfibre iscomingto thepremises, inorder torelieve theshortcomingsof thecoppernetwork,andalsoable tooutperformthepowerconsumptionof today’selectronicsolutions.Moreover,byexploiting thewavelengthdomain;optical fibre isuniquely capableof integratingserviceswithwidelydifferingcharacteristicsindependent fromeachother intoasingle infrastructure.Time-divisionmultipleaccess(TDMA)protocol,wherefunctionscanbereadilyimplementedwithdigitalelectronicsbeingusedinBPON,upto6��Mbit/ssymmetrically,GPON(GigabitPON,withspeedsupto�.5Gbit/s, forATMandalsoEthernetpacketsplusnativeTDM),andEPON(EthernetPON,optimizedforvariable-lengthEthernetpackets).Alternatively,onemayconsiderSubcarrierMultipleAccess(SCMA),requiringmorecostlyRFelectronics,orOpticalCodeDivisionMultipleAccess(OCDMA), requiringmorecostlyopticalspectrumslicing filters.Gainingpopularity isWavelengthDivisionMultipleAccess(WDMA),whereeachuserontheWDM-PONgetsan individualpairofwavelengthsforup-anddownstreamcommunication,thusineffectgettingaP�Plink(with itsadvantageofeasyper-userupgrading)onaP�MPphysicalinfrastructure.Withso-called‘colour-less’opticalnetworkunits(ONUs)attheusersideBothEPONandGPON,whichbelongtothesametechnologygeneration,canprovide1G/�G
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bandwidth.With thehuge-streambroadbandservices like IPTV,HDTV,�DTVandonlinegameplay,thebandwidthrequirementofsubscribersispredictedtoincreaseinmagnitudeperfiveyearsandwillaccelerateatpace.Takingthemiddleandlong-perioddevelopmenttrendtoanalyze, thebandwidthrequirementpersubscriberwillreach50-100Mbps.ForcurrentPONinterfaces,ofbothEPONandGPON, thebandwidthbottlenecksappear.Tosolve thisproblem, IEEEput forward10GEPONtechnologies,whichcanincreasetheupanddownstreambandwidthaswideas10Gandcanaccomplishco-existenceof10GEPONONUand1GEPONONUinonePONinterface.Thisprovidesasmoothmigrationsolutionfrom1GEPONto10GEPONforcarriers.Thusprotectscarriers’ investmentat themaximum.So,10GEPONtechnologybecomesthebestsolutionforcarrierstoconstructnextgenerationopticalaccessnetwork.
3 IEEE 802.3av 10Gbit/s Ethernet-based PON (10G EPON)TheIEEE�0�.�avPONstandardwasdevelopedtoincreasethedatarateofEPONsystemsfrom1Gbit/sto10Gbit/s, inkeepingwiththe10Gbit/sEthernet interface.Manyprotocolsaresharedbetween10GEPONwithEPON.Anamalgamationofcoarsewavedivisionmultiplexing(CWDM)andtimedivisionmultiplexing(TDM) isused inorder toallowEPONand10GEPONsystemstoco-existonthesamePON.AswithEPON,10GEPONreliesonVoIPforcarryingvoicetrafficandcircuitemulationservice(CES)forcarryingotherTDMclientrequirements.Figure1showsthe10GEPONprotocolstack.
Figure1 10GEPONprotocolstack
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IEEE�0�.�avdefines twophysical layermodes.One isSymmetric-rate 10/10G-EPONsupportstransmitandreceivedatapathsoperatingat10Gb/s.Themaindriver for10/10G-EPONis thenecessitytoprovideadequatedownstreamandupstreambandwidthtosupporttheMDU’s.Whendeploymentstrategy isMDUconfiguration,oneEPONONUmaybeconnectedup to thousandsubscribers.Andsecondis,Asymmetric 10/1G-EPONappear lesschallengingthenthesymmetricoption,asthisspecificationreliesonfairlymaturetechnology.Theupstreamtransmissionisidenticaltothatoftheexisting1G-EPON(asspecifiedinIEEEStd.�0�.�ah),andwillrelyonfield-provenandmassdeployedburst-modeoptical transceivers.Thedownstreamtransmission,whichusescontinuous-modeoptics,willrelyonthematurityof10Gb/spoint-to-pointEthernetdevices.Astheserviceandtechnologydevelops, itwill transfer tosymmetricalmode.Figure�showsthe10GEPONprotocolschedule.
4 Standardization TimelineInMarch�006,IEEE�0�.�workinggroupheldcallforinterest(CFI)for10GB/sEPONstudygroup.According to theCFImaterials, representatives fromvariousworldwidevendorsandoperatorssupported the formationof thestudygroupsuchas:Advance/NewhouseCommunications,Broadcom,CentilliumCommunications,ChinaNetcom,ChinaTelecom,ChunghwaTelecom,CiscoSystems,ClariPhyCommunicationsetc.Belowmentionedintable1arethemajormilestonesin10Gb/sEPONstudygroup:
Figure� Showsthe10GEPONprotocolschedule.
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Date Milestone
September�006IEEE�0�.�avtaskforceisformed.FirsttaskforcemeetinginKnoxville,TN.
December�007 DraftD1.0isproduced
July�00� DraftD�.0isproduced.WorkingGroupballotingbegins.
November�00� Cut-offdateforlasttechnicalchange
January�00� DraftD�.0isproduced.Sponsorballotingbegins.
September�00�(projected)
Standardapproval
Table1 MajorMilestonesin10GEPONStudyGroup
ZTEactivelyparticipates invariousstandards, including theeditorialboard thatsets the IEEE�0�.�av10GEPONstandard.Itspendssignificantamountoftimetocontributeintheformulationandimprovementof10GEPONstandards.Meanwhile,earlythisyear,GlenKramer,ChairmanoftheIEEE"10GEPON"WorkingGroup,announcedthat the10GEPONdraft for theEPONnext-generationstandardhasbeencompleted. It isexpected tobe formulated in�00�andofficiallyreleasedbymiddleof theyear.According toaWhitePaperon10GEPONpublishedby theEthernetAlliance,bothIEEEandITU-Tarecommittedtoconductmoreresearchonnext-generationopticalaccesssystems.
4.1 10 G EPON Co-existence with 1G EPONThe�0�.�avtaskforceplacessignificantemphasisonenablingsimultaneousoperationof1Gb/sand10Gb/sEPONsystemsonthesameoutsideODNplant. In thedownstreamdirection, the1Gb/sand10Gb/schannelsareseparated in thewavelengthdomain,with1Gb/s transmissionlimitedto14�0-1500nmbandand10Gb/stransmissionusing1575-15�0nmband.Intheupstreamdirection,the1Gb/sand10Gb/sbandsoverlap.1Gb/sbandspreadsfrom1�60to1�60nm;10Gb/sbanduses1�60to1��0nmband.Thisallowsbothupstreamchannelstosharespectrumregioncharacterizedby lowchromaticdispersion,butrequiresthe1Gb/sand10Gb/schannelstobeseparatedintimedomain.SincebursttransmissionsfromdifferentONUsnowmayhavedifferentlinerates,thismethodistermeddual-rateTDMA.Figure�illustratesanetworkwhereanOLTsupportsamixofEPONONUs,ONUswith10Gbit/sdownstreamand1Gbit/supstream,andONUs10Gbit/supstreamanddownstream.NotethatWDMtechniqueisusedtoseparatethe1Gbit/sand10Gbit/strafficinthedownstreamdirectionandcombinationofWDMandTDMisusedintheupstreamdirection.Thediscoveryandotherprotocolextensionstosupporttheco-existence
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5 Power BudgetThe�0�.�avdefinesseveralpowerbudgets,denotedeitherPRorPRX.PRXpowerbudgetdescribesasymmetric–ratePHYforPONoperatingat10Gb/sdownstreamand1Gb/supstream.PRpowerbudgetdescribessymmetric–ratePHYforPONoperatingat10Gb/sdownstreamand10Gb/supstream.Eachpowerbudget isfurther identifiedwithanumericrepresentationof itsclass,wherevalueof10representslowpowerbudget,valueof�0representsmediumpowerbudget,andvalueof�0representshighpowerbudget.To increaseopticalpowerbudget, it is regulatedthat10GEPONtechnologymustbeabletoachieveFECwhichusesRS(�55,���)coding.10GEPONcurrentlystandardizethreetypesofpowerbudget:PR10/PRX10,PR�0/PRX�0andPR�0/PRX�0.Table�listspowerbudgetinformation.10GEPONPowerBudget
ofEPONand10GEPONONUsarediscussedintheappropriatesectionsbelow.Thekeyfeaturesofthe10GEEPONarchitectureisthatitallows10GEPONtooperateonthesameODNbackbonethatisalreadybeingusedfor1GEPON.Followingaresomeofthebenefitsassociatedtothisoneplatformfeatureare:●UsingcostefficientONUfortherequireddesiredservice●Nodisruptionoftheservicesandnetworkoperationsduringtheupgradeofthenetwork●MigrationfromEPONto10GEPONbyupgradingtheOLTthenmigratingtheONUsasneeded●ReducedOpExandCapExcostassociatedwiththismigrationofnetwork.●Innovativeimprovementondevice,enhancednetworkcapabilityandoptimizationsynergy●SameOAMforstrongerendtoendmonitoringwillbeusedintensively.
Figure� 10Gand1GEPONco-existence
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6 10G EPON Optical Spectrum Allocation PMDlayer isusedtorepresent the10GEPONwavelengthallocationandopticalpowerbudgetFigure � shows the IEEE�0�.�av wavelength allocation spectrum. For downstream datatransmission,itadopts1575–15�0nmbands.Forupstream,thebandis1�60–1��0nmwhichislappedover1GEPON.Thewavelengthallocationenables10Gupstreamwavelengthtooverlap1Gupstreamwavelength.So1GONUand10GONUmustusewavelengthdivisionmultiplexingmodetotransmitupstreamdata.Indownstreamdirection,10Gwavelengthand1Gwavelengthareseparated.Thisguaranteesthedownstreamdatatoenjoybroadbandwidth.
Description
LowPowerBudget
MediumPowerBudget
HighPowerBudget
Units
PRX10 PR10 PRX�0 PR�0 PRX�0 PR�0
MaximumChannelinsertionloss
�0 �4 �� dB
MinimumChannelinsertionloss
5 10 15 dB
Table� PowerBudgetExplanation
Figure4 10GEPONWavelengthAllocationChart
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7 Forward Error Correction (FEC) The10G-EPONsystemuseReedSolomon(�55,���)forwarderrorcorrection(FEC)mechanism.TheFEC ismandatory forall channelsoperatingat10Gb/s rate, i.e.,bothdownstreamandupstreamchannels insymmetric10Gb/sEPONand thedownstreamchannel in the10/1Gb/sasymmetricEPON.(UpstreamchannelintheasymmetricEPONisthesameasin1Gb/sEPON,i.e.,optional frame-basedFECusingRS(�55,���).).The10G-EPONtaskforcealsofocusesondefininganewphysicallayer,keepingtheMACarchitecture.Thismeansthatusersof10G-EPONcanexpectbackwardcompatibilityofnetworkmanagementsystem(NMS),PON-layeroperations,administrations,andmaintenance(OAM)system,DBAandscheduling.
8 Dynamic Bandwidth Allocation (DBA)10GEPONsystemis theability toovercomesystembottlenecksand log jamsviaadjustments intheEPONDBAalgorithm.TheDBAcyclelengthandbandwidthallocationperONUcanbeadjustedandasaresulttotalOLTupstreamtransmissiongoingintotheswitchwillbe"smoother",lessburstyinnature,allowingcarrierstoovercomeblockingelementsintheirnetworktopology(e.g.assigningmorebandwidthtotheOLTportsthentheuplinkportsintheswitchconnectedtotheOLTtosaveCAPEX).
9 10G Convergence Figure5showstheconvergenceneedofEPONandGPONsystemsthatcurrentlyusedifferentphysical layersstructures,which leadsto incompatiblechips,hardwareandopticalmodules. ITUandIEEEarediscussingaplanforconvergenceoftheirspecificationsatthephysicallayerin10Gthatwouldallowforthesharedandconvergenceofthechips,opticsandhardwareplatforms,thusdrivingcostsreductions.Carrierswouldstillhaveachoiceoftechnologiesin10GPON,butwouldhavetheadvantagesofasinglephysicallayer.Thatconvergedsystemispossiblefeasibleinwhichonlydifferenceswillbeleftathigherlevel.AndasaresultconvergencebringsunifiedOAM,ODNandservicemodels.
Figure5 Convergencesat10G
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10 10G EPON Industrial ChainHardwaremanufacturerswhohave invested in10GEPON technologymainly includeopticalmodulemanufacturers,chipmanufacturersandequipmentmanufacturers.Recently,Vitesse, theICsolutionsupplier,announcedtosupplyawholesetofPMDrelatedchipsfor10GEPONuse.Thissetofchipscomplieswith IEEE�0�.�av/D�.0protocol.For10GEPONopticalmodule,asearlyasthefirsthalfyearof�00�,thereweresupplierstoprovideasymmetricalopticalmodules.Andnow,thesupplier isabletoprovideXFPasymmetricalopticalmodules inbatches.Andfromthe4thquarterof�00�on, theycanalsoprovidesymmetricalopticalmodules.Japan'scompanyMitsubishiannounceditresearchedanddevelopedsuccessfully10GEPONsampleequipmentand10GEPONopticalmoduleatFSANconferenceinSeptemberof�00�.Astochipmanufacturers,companyPMC-Sierraplayedaleadingroleindemonstrating10GEPONtechnologyinJulyof�00�.ThedemonstrationusedPMC-Sierracomplete10GEPONreferencedesign including10GOLT)PAS�001and10GONUPAS�001.ThissystemhadbeenlaunchedatOpticalNetworkForumofChina,BeijingfromMay��to��.TKNOVUScompanyalsoannouncedits10GEPONEVBfullycompliedwithIEEE�0�.�av10GEPONprotocol.ThissetofEVBsystemincludedOLTandONUequipmentand integrateddevelopmenttools.Astotelecommunicationequipmentmanufacturers,ZTE firstly brought forward 10G EPON sample equipment in the industry at InternationalInformationandCommunicationExpoofChinaonOctober��nd,�00�andperformedsystemservicedemonstration.Thedisplayedsampleequipment includesxPONCOequipment,whichsupportsEPON,GPON,10GEPONand10GGPONintegratedplatform,andMDUequipment.Thedemonstrationcovers10GEPONbroadbandperformanceandperfectcompatibilityof10Gand1GEPON.TheseriesofequipmentevolutesbasedoncurrentxPONequipmentsmoothmigrationandenabletoimprovethecapabilityofsystemaccessbandwidthenlargementandserviceaccess.
11 ConclusionInnutshell,fromtheabovebriefanalysis,wecanconcludethat10GEPONprotocoldevelopsveryfast.Therequirements todeploynetworks thatservice thesenewdata intensiveandbandwidthhungryvideoapplicationswillspurdemandforsystemsthatsupplementandevolve,rather thanreplace,existingequipment inthe infrastructure.Thismigrationandacceptabilityofnewstandardprotocols isagreatsourceofTCOOptimizationandcost reductions.ThesenetworkswillmovefromsystemsbasedonavarietyofprotocolstosystemsbasedprimarilyonEthernettechnologies.Andtheformalprotocolistobepublishedinthe�rdquarterof�00�.10GEPONcannotonlyinheritEPONlarge-scaledeploymentexperiencesbutalsoco-existwithGEPONwithoutchangingexistingODNnetwork,thussavesalotofcostforcarriers.
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