Cisco城域接入网络解决方案Cablemodem

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1、Cisco城域接入网络解决方案---CableAgendaCiscoCATVSolutionProductUpdateTheCiscoAdvantageNodeHeadend/RegionalDataCenterNodeNodeHubHubNodeNodeNodeHubNodeCOAXTapNodeNodeDrop600-2000HomesDropHomeArchitectureDistributionArchitectureHUBArchitectureCable系统一个有限电视网的5个主要部件

2、体系结构部件头端中继电缆邻域中的分布电缆分接电缆终端设备(电视、电缆调制解调器、机顶盒等)电缆系统拓扑(光纤节点)从/到头端级联中一般不到5个放大器一个节点一般支持200--2000个家庭树和枝杈系统头端光纤节点中继电缆激活一个双向网络RHE(地区头端)其他来源ModulatorandScramblerForEachChannelFiberRackTX/RX本地头端HFCLHELHE光纤双向LCUpConverteruBR7246光纤节点电缆调制解调器TapTVReceiverModula

3、torandScramblerReceiverHub示意图FastEther/Gig-EtherModulatorsAMandDigitalChannelsUniversalBroadbandRouterRFRFMCNSDownMCNSUpOC-48SONET/SDH/...Upconverter，射频调制HL混频器7204MPS有线电视网(HFC)的接入模拟电话UBR7246CableRouterHFC数据网CableModemUBR924/SmallCablerouter/机顶盒铜轴电缆5-4

4、2MHz铜轴电缆以太网PCTVTV下行27-40Mbps/Modem上行nx(2.5-5Mbps)/Modem,n=1,2,4,6uBR7246CombinerCHACHBCHCCHDLocalFeedCombinerEachsetofhomesseestheirprimarydownstreamchannelDownstream:FrequencyConverter有线电视网(HFC)的接入HFCuBR7246UpstreamterminateonrespectiveLineCardUpstrea

5、ms:有线电视网(HFC)的接入HFCSampleCablePlantLayoutupstreamdownstreamfutureDOCSISOOBDAVICAnalogTVDigitalTV0Mhz750Mhz42MhzNote:thefrequenciesforanalogvs.digitalarearbitrary;onlymust-carrylawsdictatechannelplacement.CableChannel•NTSC-USA-6MHz-27/36Mbit/sec•PAL-Eur

6、ope-8MHz-36/46Mbit/sec•64/256QAM-RFModulateddigitalsignal-QuadratureAmplitudeDataRatesFreqRangeMHzTDMACarrierQAM-2568b/SymQAM-646b/SymQAM-164b/SymQPSK2b/Sym54-86054-86054-86054-8605-425-425-425-42ChannelWidthMHz68681.63.21.63.2BaudRateMSps5.36057.155.0

7、576.741.282.561.282.56RawBitRateMbps42.8857.230.3440.445.1210.242.565.12PayloadRateMbps~38~57~27~36~4.6~9~2.3~4.6目前使用DOCSISDataOverCableNetworksOSIHigherLayersTransportNetworkDataLinkPhysicalApplicationsTCPorUDPIPIEEE802.2DOCSISMACHFCUpStreamTDMA(Mini-

8、Slots)5-65MHz(QPSKorQAM-16)DownStreamTDMA(MPEG)Band6MHz(QAM-64orQAM-256)DOCSISControlMessagesCASEBackboneDataCenter/HeadendVoDServersCiscoCatalyst6000CiscoGSR12000MiddlewareServerCiscoCableTroubleshooterCiscoCacheEngineSatelliteAntennaC