optical access networksnew

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1、OpticalAccessNetworksAccessNetworksandFullServiceProvidersArchitecturesandClassificationofAccessNetworksAlternativeAccessTechnologiesFibreAccessNetworks:FTTCab,FTTC/B,FTTB/HPONArchitectures:AF,TPON,WPON,WRPONAPON/BPON,EPONandGPONFutureDevelopmentsOpticalAccessNetworks-1-byHe

2、nriqueJ.A.daSilva,2005.03.09AccessNetworksandFullServiceProvidersThenetworksfeedingthemetro(andcore)networksbygatheringdatafromtheendusers(us).ThetwomaincontendersareCATVcompaniesandphonecompanies.Thisisduetothetwoexistingnetworkinfrastructures:Telephone(POTS)networks(xDSL);

3、CableTVnetworks(CableModems).Sinceexistingcableinfrastructuresareavailable,operatorstryto“milk”theirnetworkstoprovidedataservicessuchashighspeedInternetaccess.Thisrequiresupgradingthoseinfrastructures,toovercomethe4kHzlimitedunidirectionalbroadcast.Servicescanbeswitched/broa

4、dcast,symmetrical/asymmetrical,unidirectional/bidirectional,andcanbeprovidedwithdifferentbandwidths.OpticalAccessNetworks-2-byHenriqueJ.A.daSilva,2005.03.09ServicesSupportedbyAccessNetworksServiceTypeDownstreamBandwidthUpstreamBandwidthTelephonySwitched4kHz4kHzISDNSwitched14

5、4kbit/s144kbit/sVideoBroadcastingBroadcast6MHzor2to6Mbit/s0InteractiveVideoSwitched6Mbit/sSmallInternetAccessSwitchedSomeMbit/sSmall(initially)Video-ConferenceSwitched6Mbit/s6Mbit/sEnterpriseServicesSwitched1.5Mbit/sto10Gbit/s1.5Mbit/sto10Gbit/sDownstream:fromtheserviceprovi

6、dertotheuser.Upstream:fromtheusertotheserviceprovider.FullService:provisionofalltheservicesavailablethroughaccessnetworks.CriteriaforClassificationofServicesBandwidthrequirements.Symmetrical(bidirectional)orAsymmetrical(unidirectional).BroadcastorSwitched.OpticalAccessNetwor

7、ks-3-byHenriqueJ.A.daSilva,2005.03.09ArchitecturesforAccessNetworksNIUH=HubRNRN=RemoteNodeNIU=NetworkInterfaceUnitANIUmaybelocatedintheHRNNIUpremisesofonesubscriberormayserveseveralsubscribers.TheHubisusuallypartofalargernetwork,RNNIUbutmaybeconsideredasthesourceofdataforthe

8、NIUsandthedestinationfordatacomingfromtheNIUs.FeederNetworkDistributionNetw