Cisco Systems UBR7225VXR specifications Upstream RF Channel Transmission Characteristics

Page 131

Appendix B RF Specifications

DOCSIS 1.0 Transmission Characteristics

Table B-3 DOCSIS 1.0 Assumed Downstream RF Channel Transmission Characteristics (continued)

Parameter

Value

 

 

Seasonal and diurnal signal level variation

8 dB

 

 

Maximum analog video carrier level at the cable modem

17 dBmV

input, inclusive of above signal level variation

 

 

 

Lowest analog video carrier level at the cable modem input,

–5 dBmV

inclusive of above signal level variation

 

 

 

1.For measurements above the normal operating frequency band (except hum), impairments are referenced to the highest-frequency NTSC carrier level.

2.This presumes that the digital carrier is operated at analog peak carrier level. When the digital carrier is operated below the analog peak carrier level, the carrier-to-noise ratio may be less.

3.Decibels relative to carrier, a common measurement in RF engineering to specify the power of a sideband in a modulated signal relative to the carrier in decibels.

4.For hum measurements above the normal downstream operating frequency band, a continuous-wave carrier is sent at the test frequency at the same level as the highest-frequency NTSC carrier.

Upstream RF Channel Transmission Characteristics

Transmission is from the cable modem output at the customer location to the headend. Measurement methods are defined in NCTA or CableLabs2 documentation.

Table B-4

DOCSIS 1.0 Assumed Upstream RF Channel Transmission Characteristics

 

 

 

Parameter

 

Value

 

 

 

Frequency range

 

5 to 42 MHz edge to edge

 

 

Transit delay from the most distant cable modem to the

0.800 msec (typically much less)

nearest cable modem or CMTS

 

 

 

Carrier-to-noise ratio

Not less than 25 dB

 

 

Carrier-to-ingress power (the sum of discrete and broadband

Not less than 25 dB1

ingress signals) ratio

 

 

 

Carrier-to-interference (the sum of noise, distortion,

Not less than 25 dB

common-path distortion, and cross-modulation) ratio

 

 

 

Carrier hum modulation

Not greater than –23 dBc (7%)

 

 

 

Burst noise

 

Not longer than 10 μsec at a 1-kHz average rate for most

 

 

cases2, 3

Amplitude ripple

5 to 42 MHz: 0.5 dB/MHz

 

 

Group delay ripple

5 to 42 MHz: 200 ns/MHz

 

 

Micro-reflections—single echo

–10 dBc @ 0.5 microseconds

 

 

–20 dBc @ 1.0 microseconds

 

 

–30 dBc @ > 1.0 microseconds

 

 

Seasonal and diurnal signal level variation

Not greater than 8 dB min to max

 

 

 

1.Ingress avoidance or tolerance techniques may be used to ensure operation in the presence of time varying discrete ingress signals that could be as high as 0 dBc. (CableLabs1)

2.Amplitude and frequency characteristics sufficiently strong to partially or wholly mask the data carrier.

3.Impulse noise levels more prevalent at lower frequencies (<15 MHz).

Cisco uBR7225VXR Universal Broadband Router Hardware Installation Guide

 

OL-17309-02

B-3

 

Image 131
Contents Text Part Number OL-17309-02 Americas HeadquartersPage N T E N T S AC Power Measuring the Downstream RF Signal at the Upconverter Output Maintaining the Cisco uBR7225VXR Router Coaxial Cables C-1 Viii Revision Date Change Summary PrefaceDocument Revision History Document ObjectivesChapter Title Description AudienceDocument Organization Appendix G, Site Log Document ConventionsObtaining Documentation and Submitting a Service Request Cisco uBR7225VXR Universal Broadband Router Cisco uBR7225VXR OverviewOL-17309-02 Cable interface line card slot Cisco uBR7225VXR Router ChassisCard Slot and Logical Interface Numbering Cisco uBR7225VXR Network Interface OverviewCisco uBR7255VXR Chassis and Cable Interface Line Cards MAC-Layer AddressBasic Internet Access Services Supported System Configurations OverviewTwo-Way HFC Cable Network Example IP Telephony Services VPN ServicesHFC Telco ReturnNetwork Processing Engine Hardware Component DescriptionsNPE Comparisons Cisco Cable Interface Line Cards Power Supplies Fan Trays Cisco uBR7225VXR AC-Input Power SupplyCisco uBR7225VXR Fan Tray Internal Airflow-Top View Subchassis and Midplane Cisco uBR7225VXR ChassisTop Back CompactFlash DiskCisco uBR7225VXR Overview Hardware Component Descriptions OL-17309-02 Safety Recommendations InstallationLifting the Cisco uBR7225VXR Router Safely Lifting the Chassis Cisco uBR7246 Router Shown Safety with ElectricityPreventing Electrostatic Discharge Damage Site Environment AC PowerSite Requirements Specification Minimum Maximum Site Configuration Maintaining Normal OperationGeneral Precautions Before You Begin Power ConsiderationsRequired Network Information Rack-Mount and Cable-Management Kit Installation ToolsShipping Container Contents Equipment Required to Verify Your Plant’s RF SetupTwo-Way Data and VoIP Provisioning the Cable HeadendReceivers Headend CertificationDiplex Filters DHCP, DNS, TFTP, and TD Servers Dial-Up/Remote Access ServersVoIP Sgcp Pass-Through Authentication, Authorization, and Accounting ServersVoIP Gateways and Gatekeepers Interference Considerations Headend WiringEquipment Racks 17.32 23.875 21.875 Task Verified By Date Site Preparation ChecklistTask Verified By Date Component ChecklistsCisco uBR7225VXR Router Installation Checklist Installing the Cisco uBR7225VXR RouterCisco uBR7225VXR Router Chassis Rack-Mounting Options Typical 4-Post Equipment Rack Posts and Mounting Strips Rack-mount bracket Cable-Management Bracket Requirements Installing the Chassis in a Telco-Type RackRack-mount bracket Cable-management bracket Installing Rack-Mount Brackets on the Rear of the Chassis Installing the Brackets on the ChassisInstalling Rack-Mount Brackets on the Front of the Chassis Installing Rack-Mount Brackets in the Middle of the Chassis Installing the Chassis in the Rack OL-17309-02 OL-17309-02 Cabling Console and Auxiliary Port Connection Equipment Connecting Cable Interface Line Card CablesPin Signal Direction Description Console Port SignalsAuxiliary Port Signals Protective Grounding Connecting PowerConnecting to the AC-Input Power Supply 14 Connecting AC-Input Power Powering On the Cisco uBR7225VXR RouterConfiguring the Interfaces OL-17309-02 Connecting the Cisco uBR7225VXR Router to the Cable Headend Two-Way Data Headend Architecture RF and Digital Data Overview One-Way Data Headend ArchitectureInstalling and Configuring the Upconverter Connecting and Configuring the DownstreamMeasuring the Downstream RF Signal Page Viewing the Downstream if Signal on a Spectrum Analyzer Measuring the Downstream RF Signal at the Upconverter Output Overloaded Spectrum Analyzer Input Page OL-17309-02 OL-17309-02 OL-17309-02 OL-17309-02 OL-17309-02 OL-17309-02 OL-17309-02 OL-17309-02 Channel Bandwidth Cisco MC11 Fpga Connecting and Configuring the UpstreamConnecting the Upstream to the Optical Receiver Docsis Specification30 km Fiber node Milliwatt Measure +10 dBmV at this point Testing the Upstream ConfigurationOptical receiver Downstream Optical +10 dBmV Receiver +13 dBmV Attenuator Measuring the Upstream RF Signal Using a Spectrum Analyzer Measuring the Upstream RF SignalOL-17309-02 OL-17309-02 29 Analyzing the Upstream RF Signal-64-Byte Data Packets Analyzing the Upstream RF Signal30 Analyzing the Upstream RF Signal-1500-Byte Data Packets OL-17309-02 Symbol Rate +/-1/2 Symbol Rate Bandwidth Using the Zero-Span Method with Adjacent Upstream ChannelsCenter Frequency Minimum Resolution OL-17309-02 35 Vector Signal Analyzer Plot of Upstream Data Burst OL-17309-02 OL-17309-02 OL-17309-02 39 Preamble Amplitude Before Center Frequency Adjustment 41 Original Preamble Viewed with Accelerated Sweep Time OL-17309-02 Connecting the Cisco uBR7225VXR Router to the Cable Headend OL-17309-02 Connecting the Cisco uBR7225VXR Router to the Cable Headend Configuring the Digital Signal OL-17309-02 OL-17309-02 Online Insertion and Removal Maintaining the Cisco uBR7225VXR RouterEnvironmental Monitoring Environmental Monitoring and Reporting FunctionsParameter High Warning High Critical Shutdown Reporting FunctionsRouter# show environment Temperature ranges and values are subject to change Fan Failures Providing Information TroubleshootingOverview Troubleshooting Problem Solving with Subsystems Problem Solving with SubsystemsIdentifying Startup Problems Cooling Subsystem Power SubsystemProcessor Subsystem Troubleshooting the Network Processing EngineTroubleshooting Cable Interface Line Cards Other Troubleshooting Information Websites Verifying the Downstream SignalTroubleshooting Verifying the Downstream Signal Description Specification Cisco uBR7225VXR Router SpecificationsBroadband Routers at the following URL Channel Qpsk Raw RF SpecificationsChannel Symbol Rate Raw Data Rate Nominal Data Bandwidth, MHz Msym/sec Mbps Rate, MbpsParameter Value Docsis 1.0 Transmission CharacteristicsDownstream RF Channel Transmission Characteristics Upstream RF Channel Transmission Characteristics Docsis 1.1 Transmission Characteristics EuroDOCSIS Transmission Characteristics Downstream RF Channel Transmission Characteristics Upstream RF Channel Transmission Characteristics Electrical Input and Output Parameter Value OL-17309-02 Coaxial Cables Cable SpecificationsIdentifying an RJ-45 Rollover Cable Console and Auxiliary Port Cables and PinoutsRJ-45-to-DB-9 Console Port Cables and PinoutsIdentifying an RJ-45 Crossover Cable Fast Ethernet Port Cables and PinoutsAuxiliary Port Cables and Pinouts RJ-45 Pin Description Identifying an RJ-45 Straight-Through CableRJ-45 Pin Figure C-5 Duplex SC Cable Connector Fiber-Optic Cables and ConnectorsAbout Wiring Standards Industry-Standard Wiring PlansPosition Color Optical Fiber Color CodesTIA/EIA Standards Information Pair Number Wire Number Solid Color Stripe Color Pin Number Telephone Wire Color CodesPair Number Wire Number Solid Color Stripe Color Pin Number White Blue Green Red Orange Black Yellow Pair Number Wire Number Solid Color Stripe ColorOL-17309-02 Http//developer.apple.com Http//atxnetworks.com Frequency Allocation TablesB1, G D1, K Standards ComparisonsNtsc Cable Television Channels and Relative Frequencies Freq MHz Carrier Visual Aural Table E-4 Freq MHz Carrier Visual Aural Table E-4 Ntsc M Cable Television Frequencies for Japan Table E-5 Japanese Channel Assignments Bandwidth Visual Carrier Aural Carrier PAL/SECAM Cable Television Channels and Relative FrequenciesChannel Channel Bandwidth Visual Carrier Aural Carrier Number MHz Table E-6 OL-17309-02 Manufacturer Website or Phone Number Products/Model Manufacturers for Headend Provisioning RequirementsNorth American Channel Plans Agilent Agilent 89411A European Channel Plans Agilent Agilent 8591C Tektronix 2715 Sunrise Telecom AT2000R Site Log Initials Symbols GL-2 GL-3 GL-4 GL-5 GL-6 D E IN-2 IN-3 IN-4 IN-5 IN-6 IN-7 IN-8
Related manuals
Manual 20 pages 35.92 Kb