Deploying Cable Access Infrastructures

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Deploying Cable Access Infrastructures Powered By Docstoc
					                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                     1




                                                     Deploying Cable
                                                   Access Infrastructures
                                                                                        Session SPL-230




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                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                     2




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                          Speaker



                                       • Joel T. McKelvey
                                       • Cable Communications Specialist
                                       • Service Provider Line-of-Business
                                       • mckelvey@cisco.com



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                          Agenda


                                               • Overview
                                               • References and Specifications
                                               • Cable Access Infrastructure Design Goals
                                               • Characterization of the Cable Plant
                                               • DOCSIS Equipment and Offerings
                                               • Deployment of DOCSIS Design
                                               • Case Studies
                                               • Questions



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                                                                                         Overview



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                          Design Success Questions


                                     • Is the RF network DOCSIS Compliant?
                                     • Is the network designed for added
                                       services?
                                     • Do data rates support usage?
                                     • Is the architecture easily scalable?
                                     • Did we design for the future?


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                          Driving Factors for Design Success


                                     • A Design that meets our goals
                                       will include:
                                                Demographics Input
                                                Appropriate QoS Settings
                                                Enough BW in the IP *and* RF Domain to
                                                meet Penetration
                                                Sane Address Management



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                          Design Elements of
                          Successful Deployments

                                     Strive for:

                                                                         • Functionality
                                                                         • Scalability
                                                                         • Adaptability
                                                                         • Manageability
                                                                         • Cost Effectiveness


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                          Elements of Successful Design

                         Terms and                                                                 Deployment
                         Specifications                                                            Goals




                         Existing Cable                                                            DOCSIS
                         Infrastructure                                                            Equipment




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                          You have the KEY!


                                                                                        PLANNING
                                                                                         is the
                                                                                          KEY
                                                     to a successful Data over
                                                         Cable Deployment!


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                          Agenda


                                               • Overview
                                               • References and Specifications
                                               • Cable Access Infrastructure Design Goals
                                               • Characterization of the Cable Plant
                                               • DOCSIS Equipment and Offerings
                                               • Deployment of DOCSIS Design
                                               • Case Studies
                                               • Questions



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                                 References and Specifications




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                          White Paper Resources
                                • Multimedia Traffic Engineering for HFC Networks
                                http://www.cisco.com/warp/public/cc/so/cuso/sp/hfcn_wp.pdf


                                • Combined Wisdom on the Upstream
                                http://www.cisco.com/warp/public/cc/so/cuso/sp/mllt_wp.pdf


                                • Successfully Deploying Data Over Cable Networks:
                                  An Overview
                                http://www.cisco.com/warp/public/cc/so/cuso/sp/dcsis_wp.pdf


                                • Business Case for Two-Way Service Deployment over
                                  HFC Network
                                http://www.cisco.com/warp/public/cc/so/cuso/sp/2way_pl.pdf

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                          Measurement Units


                            • dB - Decibel. A measure of the relative strength of two signals.
                              Multiplication becomes addition and division becomes
                              subtraction.

                            • dBm - Decibels with respect to one milliwatt. A unit of RF signal
                              strength used in satellite work and other communications
                              applications.

                            • dBmV - Decibels with respect to 1 millivolt in a 75-ohm system.
                              The unit of RF power used in CATV industry. Based on 10 log X
                              functions.

                            • 0 dBmV = 1 millivolt measured across an impedance of 75 ohms



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                          Terms

                            • CATV - Community Antenna TV
                            • HFC - Hybrid Fiber Coaxial. The dominant physical layer CATV
                              design for 2-way systems
                            • NTSC - National Television Systems Committee: U.S. TV
                              technical standard, named after the organization that created it
                              in 1941. Uses a 6 MHz wide modulated signal.
                            • PAL - Phase Alternating Line. The TV system used in most of
                              Europe and many other places, in which the color carrier phase
                              definition changes in alternate scan lines. Utilizes an 8 MHz
                              wide modulated signal.
                            • SECAM - Systemme Electronic pour Couleur Avec 3 Memoir. TV
                              system used in France and some former Soviet bloc countries.
                              Utilizes an 8 MHz wide modulated Signal.


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                          Terms

                            • Carrier-to-Noise - C/N (also CNR): The difference in
                              amplitude between the desired RF carrier and the noise in
                              that portion of the spectrum
                            • Signal-to-Noise - S/N (also SNR): Similar to C/N but relates
                              to a Baseband signal
                            • Ingress Noise - Over-the-air signals that are inadvertently
                              coupled into the nominally closed coaxial cable
                              distribution system. Difficult to track down and
                              intermittent in nature.
                            • QPSK - Quadrature Phase Shift Keying. A digital
                              modulation method in which the there are 2 data bits
                              represented with each baud symbol.


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                          Terms


                             • QAM - Quadrature Amplitude Modulation. A digital modulation
                               method in which the value of a symbol consisting of multiple
                               bits is represented by amplitude and phase states of a carrier.
                               Typical QAM types are 16-QAM (4 bits per symbol), 64-QAM (6
                               bits per symbol), and 256-QAM (8 bits per symbol).
                             • Downstream(DS) - Signal flow from headend toward
                               subscribers. Also called Forward Path.
                             • Upstream(US) - Signal flow from the subscribers to the
                               Headend. Also called the Return or Reverse Path.
                             • SID - Service ID: a number that defines (at the MAC sublayer) a
                               particular mapping between a cable modem and the CMTS.



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                          Terms


                            • FDM - Frequency Division Multiplexing. A data transmission
                              method in which a number of transmitters share a transmission
                              medium, each occupying a different frequency.
                            • Headend - The location where the Cable company aggregates,
                              combines, mixes, and modulates all signals in order to send
                              them downstream and receive upstream signals.
                            • HHP - Households Passed
                            • DPT - Dynamic Packet Transport
                            • SRP - Spatial Reuse Protocol. (Technical name for DPT)




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                          International Split Plans

                       Region or Country                                                                                                               Split Plan
                                                                                                                                                       Split Plan
                       North, Central, and South America,                                                                                              40/52
                                                                                                                                                       40/52
                       China, Korea, Phillipines, Thailand,
                                                  Thailand,
                       Singapore
                       Australia                                                                                                                       65/85
                                                                                                                                                       65/85
                       Japan, New Zealand                                                                                                              55/70
                                                                                                                                                       55/70
                       India, Malta, Eastern Europe                                                                                                    30/48
                                                                                                                                                       30/48
                       Western Europe, Ireland, United                                                                                                 65/85
                                                                                                                                                       65/85
                       Kingdom


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                          Frequency Allocation
                                                                                                         ASTRONOMY                                            AIR TRAFFIC
                                                                                                         AERO NAVIGATION                                      CONTROL 136
                                                         CB HAM                       HAM                                                                                            MHz
                                        SHORTWAVE              LAND MOBILE                 TV CHANNELS        TV CHANNELS            FM     AERO NAVIGATION                HAM
                     OVER AIR           HAM                    RADIO & PAGING              2-4                5-6                           AIRCRAFT VOICE    RESEARCH     OTHER

                     CABLE                                                                 2                          6        A-6                A-1 A                              E
                                      5.75                                          50 - 54           72 76               88              108        (14)                      (18) 150

                     OVER AIR                                      Various RF Transmission
                     CABLE
                               150     (19)                                                                                                                                300 (36)
                                                                                                                                     6 (MHz)

                     OVER AIR                                      Various RF Transmission
                     CABLE                                                                                                                                           450 (61) AA



                     OVER AIR                                      Various RF Transmission
                     CABLE
                                                                                                                                                                         600 (86)
                             450 (63) ZZ
                                                                                                                Channelization Plans
                     OVER AIR        Various RF Transmission
                                                                                                                      EIA Standard
                     CABLE                                                        1000        (100)                   HRC (Harmonically Related Carrier)
                              600    (87)
                                                            750
                                                                                                                      IRC (Incrementally Related Carrier)
                          TROUBLE AREA FOR CATV
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                          Symbol Legend

                                                                                  Head End                        Laser/Fiber


                                                                                  Satellite                       Hub
                                                                                  Antenna

                                                                                  RF                              Bi-Directional
                                                                                  Amplifier                       Amplifier


                                                                                  Splitter                        8-Way Tap


                                                                                  Fiber
                                                                                                                  Fiber Receiver
                                                                                  Transmitter


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                          IP over Cable TV Network

                           Cable Network with IP Access
                                                                                                                   uBR7246vxr
                     Feed Types:
                                                                                                      Node        Broadband Router
                     Off-Air
                                                                                                                           < 100 Channels
                     Coax
                                                                                                                                  CNN
                     SatCom                                                             Hub                                      HBO
                                                                                                                                  A&E
                                                                                                                                 ESPN
                                                                                                                                  TBS
                                                            RDC                                               Node
                                                                                              Hub
                         PSTN
                                                                                                           Node
                                                                                                                  COAX
                              Internet
                                                                                                                                Tap
                                                                                                     Node
                                                                             Hub

                                                                                                                          Drop

                                              Node             Node             Node               Cable
                                                                                               Modem PC
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                          Specs for Success



                                                    Typical DOCSIS Per Downstream Bandwidth*

                                                                 Downstream              64-QAM       256- QAM
                                                                  Bandwidth             Throughput   Throughput

                                                                        6 MHz            27 Mbps      38 Mbps


                                         * Actual usable rates minus the DOCSIS Phy and MAC overhead




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                          Specs for Success

                                                        Typical DOCSIS Per Upstream Bandwidth*

                                                                    Upstream              QPSK        16-QAM
                                                                    Bandwidth           Throughput   Throughput

                                                                      200 kHz           .272 Mbps    .546 Mbps

                                                                      400 kHz           .546 Mbps    1.108 Mbps

                                                                      800 kHz           1.108 Mbps   2.176 Mbps

                                                                    1600 kHz            2.176 Mbps   4.352 Mbps

                                                                    3200 kHz            4.352 Mbps   9.704 Mbps


                                           * Actual usable rates minus the DOCSIS Phy and MAC overhead
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                          References

                                 Web References                                                  Text References

                     • http://www.cisco.com/cable                                       •   Modern Cable Television Technology-
                                                                                            Video, Voice, and Data Communications
                     • http://www.cablemodem.com                                            by Walter Ciciora/James Farmer/David Large
                                                                                            ISBN # 1-55860-416-2

                     • http://www.cablelabs.com                                         •   Broadband Return Systems for Hybrid
                                                                                            Fiber/Coax Cable TV Networks
                     • http://www.scte.org                                                  by Donald Raskin and Dean Stoneback
                                                                                            ISBN # 0-13-636515-9

                                                                                        •   Cable Television Proof-Of-Performance
                     • http://cable.doit.wisc.edu                                           by Jeff Thomas ISBN # 0-13-306382-8


                     • http://www.catv.org



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                          Agenda


                                               • Overview
                                               • References and Specifications
                                               • Cable Access Infrastructure Design Goals
                                               • Characterization of the Cable Plant
                                               • DOCSIS Equipment and Offerings
                                               • Deployment of DOCSIS Design
                                               • Case Studies
                                               • Questions



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                                     Cable Access Infrastructure
                                            Design Goals



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                          Types of Differentiated Services

                              Differentiated Services can mean substantial
                                increases in revenue and subscriber base.


                              • Data (web, e-mail, etc.)
                              • Voice over IP (VoIP)
                              • Managed Access and VPNs
                                                                                            $
                              • Webcast Video
                                                                                        $
                              • Others


                              Each has unique design needs

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                          Planning for New Services

                                               • Determine customer requirements
                                               • Know business and practical constraints
                                               • Understand requirements of new services
                                               • Build a reference model/metrics
                                               • Engineer for existing design
                                               • Deploy
                                               • Measure results
                                               • Refine/re-plan/re-engineer
                                               • Repeat


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                          Know Your Customers!

                                               Demographics
                                               Penetration rates
                                               Homes passed
                                               Real usage patterns
                                               Customer needs/desires
                                               Types of applications in use


                                                              Understand your customers!

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                          Business and Practical Constraints



                                     • DOCSIS specifications for bandwidth
                                     • Penetration rate and service pricing
                                     • Deployment speed
                                     • Plant status and design
                                     • Real usage patterns
                          Business Case for Two-Way Service Deployment over HFC Network
                          http://www.cisco.com/warp/public/cc/so/cuso/sp/2way_pl.pdf

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                          Data Service Offerings


                              • Basic data access–email, web, etc.
                              • Different service levels–variable
                                subscription rates
                              • User self registration–avoid provisioning
                                expenses
                              • On-demand service upgrades–user
                                self provisioning


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                          Data Service Requirements



                             • Symmetric vs. Asymmetric traffic patterns
                             • Reliability/availability
                             • Delay and jitter tolerant
                             • Speed and QoS
                             • Provisioning and other challenges


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                          Delivering Voice Services

                                 • Several voice protocols -- H.323, G.711, etc.
                                 • Typically use large numbers of small packets
                                 • Extremely sensitive delay, jitter
                                 • Heavy use of upstream bandwidth
                                 • Overlap with data usage


                                 DOCSIS 1.1 mitigates many of the cable-based
                                  QoS issues associated with voice.
                                 (Voice QoS also available in Cisco’s DOCSIS 1.0+)


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                          Delivering Managed Access

                               • Can also support corporate VPN
                                 (telecommuter) services
                               • DOCSIS traffic must be differentiated
                               • QoS on DOCSIS network & backhaul
                               • Traffic monitoring and billing integration


                               MPLS-VPNs are one very elegant solution

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                          Specs for Success



                                                    Typical DOCSIS Per Downstream Bandwidth*

                                                                 Downstream              64-QAM       256- QAM
                                                                  Bandwidth             Throughput   Throughput

                                                                        6 MHz            27 Mbps      38 Mbps


                                         * Actual usable rates minus the DOCSIS Phy and MAC overhead




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                          Specs for Success

                                                        Typical DOCSIS Per Upstream Bandwidth*

                                                                    Upstream              QPSK        16-QAM
                                                                    Bandwidth           Throughput   Throughput

                                                                      200 kHz           .272 Mbps    .546 Mbps

                                                                      400 kHz           .546 Mbps    1.108 Mbps

                                                                      800 kHz           1.108 Mbps   2.176 Mbps

                                                                    1600 kHz            2.176 Mbps   4.352 Mbps

                                                                    3200 kHz            4.352 Mbps   9.704 Mbps


                                           * Actual usable rates minus the DOCSIS Phy and MAC overhead
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                          Don’t Forget the Backhaul


                            The backhaul network (the part of the
                             network between the CMTS and the ISP)
                             must support:


                            • Service bandwidth needs
                            • QoS requirements
                            • Service excellence (stability, availability, etc.)


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                          Determining Traffic Metrics




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                          Traffic Engineering

                              • Average bandwidth: perceived traffic rates over
                                time. Useful for long-duration measures.
                              • Peak bandwidth: determined by numbers of
                                users simultaneously accessing media.
                              • Max bandwidth: highest speed experienced by
                                users. Typically used for rate limiting.
                              • Media bandwidth: theoretical maximum
                                bandwidth of the media.



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                          Data Asymmetry


                            To determine worst case asymmetry:

                            asymmetry worst case = (avg. asymmetry * avg. downstream packet size)
                                                                                          (avg. upstream packet size)


                            Sample worst case = ( 2 * 500 )
                                                                                   (64)


                            16:1 asymmetry is worst case



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                          Voice Traffic
                                To determine voice bandwidth needed:
                                • Market penetration
                                • Lines per home
                                • Traffic per home
                                Tests estimate an approximate maximum
                                 of 70 simultaneous calls per upstream
                                 at 16 QAM.
                                Bandwidth will vary based on Codec
                                 and services
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                          Traffic Engineering



                              • Bandwidth characteristics
                                         DS channel bandwidth = 6 MHz
                                         DSDR = DS QAM-64 data rate = 27 Mbps
                                         US (Up Stream) channel bandwidth = 1.6 MHz
                                         USDR = US QPSK data rate = 2 Mbps



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                          Traffic Engineering

                                     • Design assumptions
                                                All users will be Web surfing (none Web serving)
                                                Expected Penetration (10%) = 12,000
                                                Expected users per node = 100
                                                Users/Node = max. active users/node (25%) = 25
                                                DSAT = max. DS active time/active user = 25%
                                                USAT = max. US active time/active user = 25%
                                                MDSDR = min. DS data rate/user = 270 Kbps
                                                MUSDR = min. US data rate/user = 40 Kbps


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                          Traffic Engineering

                            • Design calculations
                                      Possible users/DS = DSDR/(DSAT * MDSDR) = 400
                                      Possible users/US = USDR/(USAT * MUSDR) = 200
                                      Possible users/DS (using 1x4 LC) = 200 x 4 = 800
                                      Limitation is DS data rate in this example
                                      Active users/DS = 400
                                      Nodes/DS = (users/DS)/(users/node) = 400/25 = 16
                                      Required DS channels = nodes/(nodes/DS) = 120/16 = 8
                                      approximately
                                      Required uBR 7246 Chassis with 8 1x4 LCs = 8/4 = TWO

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                          Per Customer BW Offering

                                     • Offer Data Rates you can meet
                                                Oversubscription is NOT a design goal
                                                Technical and Marketing need to be in sync
                                                Types of Applications in Use (HTTP, VoD, SMTP)
                                     Example:
                                                       Subscribers want 3 Mbps DS and 512 Kbps US
                                                       for 2,500 users

                                                       Problem: Single CMTS and BW available is single
                                                       DS @ 27Mbps and 3 US at 1.28 Mbps

                                                       Conclusion: This won’t work!

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                          QoS Settings



                                 • Calculate QoS based on:
                                           Average BW = (Active Subs * BW per Sub *
                                           (1 + MAC/PHY Overhead)
                                           Peak BW = (Peak Subs * BW per Sub) *
                                           (1 + MAC/PHY Overhead)
                                           Media BW = Symbol Rate * Bits per Symbol



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                          Agenda


                                               • Overview
                                               • References and Specifications
                                               • Cable Access Infrastructure Design Goals
                                               • Characterization of the Cable Plant
                                               • DOCSIS Equipment and Offerings
                                               • Deployment of DOCSIS Design
                                               • Case Studies
                                               • Questions



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                                                             Characterization of
                                                              the Cable Plant



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                          HFC Architectural Examples

                                                                      • Architectural Elements
                                                                      • Tree-and-Branch
                                                                      • HFC Rollout
                                                                      • Double Star
                                                                      • Ring
                                                                      • Cascading Hubs
                                                                      • Cascading Headends
                                                                      • Classic HFC Model

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                          Architectural Elements

                        5 Major Parts to a Cable TV Network
                                                                                                  • Headend
                                                                                                  • The Trunk Cable
                                                                                                  • The Distribution
                                                                                                    (or feeder) Cable
                                                                                                    in neighborhoods
                                                                                                  • The Drop Cable to
                                                                                                    the home
                                                                                                  • The Terminal Equipment
                                                                                                    (TV, Cable Modem,
                                                                                                    Set-Top Box, etc)


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                          Tree-and-Branch System



                                                                                 Trunk
                                                                                 Cable




                                                                                                Express Cable
                                          Headend

                                                                                        Drop
                                                                                        Cable




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                          HFC Rollout



                                                                          Fiber Cable




                                      Headend                                           Fiber
                                                                                        Node




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                          Cable System Topology
                          (Optical Node)




                       TO / FROM
                       HEAD END




                      TYPICALLY FEWER THAN FIVE AMPLIFIERS IN CASCADE

                      TYPICALLY 200 TO 2000 HOMES SUPPORTED BY ONE NODE
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                          Double Star



                                                                          Fiber Cable




                                      Headend


                                                                                 Fiber
                                                                                 Node


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                          Ring Architecture

                         SATTELITE
                         OFF AIR
                         LOCAL STUDIO                                                           H
                                                                                                            H             HUB        H
                                                                               RING
                                                                                                                           10 - 50 K HOMES
                                     PRIMARY                                                        N   N
                                     HEAD END                                                                             NODE       N
                                                                                             PT - PT                H
                                                                                         N                                 200 - 2000 HOMES


                          N                                                                                     N
                                                               N               H
                                            N
                                 N                                                                                      STANDBY
                                                                                                                        HEAD END
                                                             N                           N                              (OPTIONAL)
                                                                                                            H
                                                                                   N


                                                                                                                N
                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                                    56




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
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                          Cascading Hubs

                                                                                                     Headend


                                                              Primary Hub                                 Primary Hub


                                                                                                    Primary Hub

                                                        Secondary Hub                                     Secondary Hub


                                                                                                    Secondary Hub




                                                                                    Fiber   Fiber      Fiber
                                                                                    Node    Node       Node


                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                     57




                          Cascading Headends
                                                                                                    Super Headend


                                                                     Headend                              Headend


                                                                                                     Headend


                                                                                Hub                       Hub


                                                                                                    Hub




                                                                                    Fiber   Fiber      Fiber
                                                                                    Node    Node       Node



                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                     58




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Design Advantages
                                                                                                   HFC Network

                              • Star or Ring Provides
                                Reliability
                              • NarrowCast Capability
                              • Headend/Hub limits
                                Outages                                                 Headend

                              • SONET/SDH RING
                                overlay for reliability
                                of advanced services


                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                            59




                          HFC Scalability


                          Reliability and Increased Access Bandwidth

                            • Smaller, robust
                              serving areas:
                                     HFC to the node
                                     Alternate feed                                        COAX
                                     to the node
                                     Target nodes
                                                                                                  Drop
                                     of 500 homes
                                     Fewer amplifiers

                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                            60




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
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                          Classic HFC Network
                                                                                             100K HHP

                                                                                                         Headend

                                                                          20K HHP                              20K HHP
                                                                                 Hub                           Hub

                                                                                                         Hub

                                                                                                               40 Fiber Nodes Per Hub


                                                                                    Fiber      Fiber      Fiber
                                                                                    Node       Node       Node
                                                                                 500 HHP       500 HHP    500 HHP




                      SPL-230
                      3087_05_2001     © 2001, Cisco Systems, Inc. All rights reserved.                                                    61




                          Classic HFC Network


                                                                                                       Reality is that CATV systems
                                                       100K HHP
                                                                                                       have variable numbers of homes
                                                                                                       passed per node. Effective design
                                                                           Headend
                                                                                                       requires multiple approaches.
                             20K HHP                                                 50K HHP
                                     Hub                                             Hub               Older implementations
                                                                                                       usually have nodes supporting
                                                                          Hub                          more subscribers.

                                                                                      Multiple Fiber Nodes Per Hub


                                      Fiber               Fiber                 Fiber
                                      Node                Node                  Node
                                     500 HHP            2000 HHP 500 HHP
                      SPL-230
                      3087_05_2001     © 2001, Cisco Systems, Inc. All rights reserved.                                                    62




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
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                          Togetherness



                                           • In a Cable Modem Network RF
                                             and IP *MUST* co-exist
                                           • RF and IP are interdependent
                                           • Success relies on both RF and
                                             IP excellence


                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.   63




                          Return Path Characterization


                            • An absolute MUST
                            • Should be ongoing
                            • Key to easily finding problems
                            • Use CMTS tools to assist, (Cisco’s cable flap list)
                            • Characterize over extended periods!
                            • The deployment relies on careful Return Path
                              characterization and design


                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.   64




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Making the Return Work


                                • Use the Right Tools
                                • Plan your combining and test points carefully
                                • Ensure you have done a thorough Return
                                  Path Characterization
                                • Ensure your Nodes are not overloaded
                                  and clipping
                                • Attenuate in the proper places
                                • Design for Ingress Reduction!


                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                                          65




                          Is Your Upstream DOCSIS Compliant?

                                                   Variable                              DOCSIS Specification            Your Plant Settings

                                          Frequency Range                                  5- 42 MHz Edge to Edge

                                           Carrier to Noise
                                            (upstream)                                     Not less than 25 dB

                                              Transit Delay                                 <= 0.800 msec
                                              (Map Advance)
                                              Carrier to hum                            Not greater than -23 dBc(7.0%)

                                          Amplitude Ripple                                5- 42MHz: .5 dB/MHz

                                       Group Delay Ripple                                5- 42MHz: 200ns/MHz

                                       Digital Signal Levels                             DOCSIS Specifications

                                     From cable modem                                   +8 to +58 dBmV (QPSK)
                                        (upstream)                                      +8 to +55 dBmV (16-QAM)




                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                                          66




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Use the Right Tools


                                     • Tools
                                               Spectrum
                                               analyzers
                                               Sweep Gear
                                               Network
                                               Analyzers




                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                   67




                          Return Path Characterization




                     Low Band                                                           Peak Over Time
                     Noise

                                                                                         Single Sweep

                                                                   Upstream Channel
                                                                       20.00 MHz

                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                   68




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Spectrum Management
                                                            15.6 MHz                      17.55 MHz
                                                                                                                     Example


                                            Noise                                                      Noise

                                                                                Useable                                 Frequency
                                                                                  GAP
                                                                               (1950 kHz)

                                         • Useable gaps dictate
                                                       Upstream channel selection and bandwidth
                                                       Spectrum management options
                                                       Upstream data throughput
                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                               69




                          Useable Spectrum Gaps

                                             From
                                             From               To
                                                                 To                GAP
                                                                                   GAP     200
                                                                                           200     400
                                                                                                   400     800
                                                                                                           800     1600
                                                                                                                   1600    3200
                                                                                                                           3200
                                             (KHz)
                                             (KHz)             (KHz)
                                                               (KHz)              (KHz)
                                                                                  (KHz)   (KHz)
                                                                                          (KHz)   (KHz)
                                                                                                  (KHz)   (KHz)
                                                                                                          (KHz)   (KHz)
                                                                                                                  (KHz)   (KHz)
                                                                                                                          (KHz)
                                              5000
                                              5000              5950
                                                                5950               950
                                                                                    950    44      2
                                                                                                   2       1
                                                                                                           1        0
                                                                                                                    0       0
                                                                                                                            0
                                              6200
                                              6200              7000
                                                                7000               800
                                                                                    800    44      2
                                                                                                   2       1
                                                                                                           1        0
                                                                                                                    0       0
                                                                                                                            0
                                              7300
                                              7300              9500
                                                                9500               2200
                                                                                   2200    11
                                                                                           11      5
                                                                                                   5       2
                                                                                                           2        1
                                                                                                                    1       0
                                                                                                                            0
                                              9900
                                              9900             10100
                                                               10100               200
                                                                                    200    1
                                                                                           1       0
                                                                                                   0       0
                                                                                                           0        0
                                                                                                                    0       0
                                                                                                                            0
                                             10150
                                             10150             11650
                                                               11650               1500
                                                                                   1500    7
                                                                                           7       3
                                                                                                   3       1
                                                                                                           1        0
                                                                                                                    0       0
                                                                                                                            0
                                             12050
                                             12050             13600
                                                               13600               1550
                                                                                   1550    7
                                                                                           7       3
                                                                                                   3       1
                                                                                                           1        0
                                                                                                                    0       0
                                                                                                                            0
                                             13800
                                             13800             14000
                                                               14000               200
                                                                                    200    1
                                                                                           1       0
                                                                                                   0       0
                                                                                                           0        0
                                                                                                                    0       0
                                                                                                                            0
                                             14350
                                             14350             15100
                                                               15100               750
                                                                                    750    3
                                                                                           3       1
                                                                                                   1       0
                                                                                                           0        0
                                                                                                                    0       0
                                                                                                                            0
                                             15600
                                             15600             17550
                                                               17550               1950
                                                                                   1950    9
                                                                                           9       4
                                                                                                   4       2
                                                                                                           2        1
                                                                                                                    1       0
                                                                                                                            0
                                             17900
                                             17900             18068
                                                               18068               168
                                                                                    168    0
                                                                                           0       0
                                                                                                   0       0
                                                                                                           0        0
                                                                                                                    0       0
                                                                                                                            0
                                             18168
                                             18168             21000
                                                               21000               2832
                                                                                   2832    14
                                                                                           14      7
                                                                                                   7       3
                                                                                                           3        1
                                                                                                                    1       0
                                                                                                                            0
                                             21850
                                             21850             24980
                                                               24980               3040
                                                                                   3040    15
                                                                                           15      7
                                                                                                   7       3
                                                                                                           3        1
                                                                                                                    1       0
                                                                                                                            0
                                             24990
                                             24990             25670
                                                               25670               680
                                                                                    680    33      1
                                                                                                   1       0
                                                                                                           0        0
                                                                                                                    0       0
                                                                                                                            0
                                             26100
                                             26100             26960
                                                               26960               860
                                                                                    860    44      2
                                                                                                   2       1
                                                                                                           1        0
                                                                                                                    0       0
                                                                                                                            0
                                             27410
                                             27410             28000
                                                               28000              590
                                                                                  590      22      00       0
                                                                                                            0       0
                                                                                                                    0       0
                                                                                                                            0
                                             29700
                                             29700             40000
                                                               40000             10300
                                                                                 10300     51
                                                                                           51      25
                                                                                                   25      12
                                                                                                           12       6
                                                                                                                    6       3
                                                                                                                            3

                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                               70




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Avoid Overloading and Clipping
                                                                                        UNITY GAIN CONCEPT

                             AMPLIFIER                                                                AMPLIFIER
                              (FORWARD)                                                                  ( TWO WAY)




                           ONE WAY TRANSMISSION

                                                                                   DOWN STREAM

                            INPUT                                           OUTPUT            CABLE LOSS              INPUT                OUTPUT
                            + 12 dBmV                                       + 34                - 22dB                + 12dBmV             + 34 dBmV
                                                                            dBmV
                                                           GAIN                                                                  GAIN
                                                           + 22 dB                                                               + 22 dB



                          TWO WAY TRANSMISSION
                                                                                        DOWN STREAM

                                                                                              CABLE LOSS
                                                                                                - 22dB

                                                                                               UP STREAM


                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                                                  71




                          Noise Funneling
                                                            CMTS




                                                                                                                       Noise




                           • Each House is an Antenna
                           • Ingress will destroy packets
                           • Equalize path loss to Reduce Ingress Noise
                                        Splitter



                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                                                  72




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
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                          Establishing Signal Levels


                                     +18                    +40            100 Ft                TAP                 600Ft      TAP           500 Ft            TAP
                                     dBmV                  dBmV                1 dB              (2/29)              6 dB      (2/20)        5 dB              (2/17)




                                      DROP LEVEL                                 +10          dBmV                     +12.6 dBmV                   +10 dBmV




                                                                         DROP LOSS                   100 Ft   1 dB                  100 Ft   1 dB     100 Ft    1 dB



                                                                                                       (+9 dBmV)                    (+11.6 dBmV)                        (+9 dBmV)




                      SPL-230
                      3087_05_2001         © 2001, Cisco Systems, Inc. All rights reserved.                                                                                         73




                                                                  DOCSIS Equipment
                                                                    Requirements



                      SPL-230
                      3087_05_2001         © 2001, Cisco Systems, Inc. All rights reserved.                                                                                         74




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Architectural Elements




                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.   75




                          Functionality/Manageability

                                     Does the Headend support:

                                       • Necessary IP QoS functions
                                       • Routing requirements for services
                                       • Security feature set (DOS, TOS)
                                       • Management interface/tools
                                       • Debugging and troubleshooting
                                       • Field-tested DOCSIS algorithms


                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.   76




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Scalability/Adaptability

                                     Does the Headend support:


                                 • DOCSIS density for now and the future
                                 • Appropriate backhaul technologies
                                 • Large-scale provisioning
                                 • Traffic model equal to deployment
                                 • Future upgrades for new services/subs


                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.   77




                          Cost Effectiveness



                              The most cost effective design is one
                               that supplies service excellence
                              • Minimal downtime or service interruption
                              • Strong system-wide design
                              • Planning for the future


                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.   78




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Services to Support

                                     Analog video on RF




                                                                                                        Video
                                                                                                                Voice
                                                                                                                        Web
                                     Digital video:
                                                                                         Video
                                                                                                                IP
                                     MPEG/64QAM
                                                                                                        MCNS/
                                     Voice, Web, Webcast                                         MPEG
                                                                                                        MPEG
                                     Video:
                                                                                                 RF/Optical
                                        IP/MCNS/64QAM

                                                                                                                        IP Services
                                                                                                                        Digital Video
                                                                                                                        Analog Video


                      SPL-230
                      3087_05_2001    © 2001, Cisco Systems, Inc. All rights reserved.                                                  79




                          Design for Scalability - CMTS

                               • Scalable DOCSIS density – upgrade past
                                 2:8 without chassis modifications
                               • Scalable Processor speed – variety of
                                 processors available, must scale to
                                 support added services such as voice
                               • Scalable Egress technologies – flexible
                                 use of backhaul technologies to
                                 support users

                      SPL-230
                      3087_05_2001    © 2001, Cisco Systems, Inc. All rights reserved.                                                  80




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Design for Scalability – IP network


                                                    DPT/POS allow BW migration
                                                    Web Cache Valuable

                                                                                         CATV
                                                            Hub

                                          HFC                           OC12c DPT                   OC48c DPT   Internet

                                                                                        Web/Media
                                                                                         Caching
                         Optical Backbone Allows:
                         * Scalability
                         * Redundancy
                         * Investment Protection



                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                      81




                          Redundancy – CMTS


                             • Power redundancy–AC and DC options
                             • DOCSIS redundancy–RF failover without
                               modem rescan/resync
                             • Egress redundancy–backhaul networking
                             • Processor redundancy–hot failover



                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                      82




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Redundancy – IP network

                                                                                                2 RDC’s                     OC12
                                       OC12



                                                                     RDC                         OC48             RDC




                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                                   83




                          Hierarchical Design
                                                                                                    2.5 Gbps

                                                                                        GE           OC48            HUB rings     622 Mbps
                                                                                        links                       (OC-12 DPT)
                                                 GE links
                                                                                    1 Gbps
                                                                                                            RDC

                                                                Time of Day
                                                                DHCP
                                                                TFTP

                                              The Backbone is the same as any Enterprise Network

                                              The Difference is BW truly needed at the edge




                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                                   84




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Address Management



                            • Plan your Address Space
                                     Cable Networks quickly deplete addresses
                                     Use 10net for Cable Modems
                                     NAT can be misleading for advanced services
                                     Route summarization key for routing overhead



                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.   85




                                                      Deployment of
                                                    DOCSIS Infrastructure



                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.   86




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Headend Design Keys



                                                               • Key Components
                                                                              Plan Ahead
                                                                              Keep Records
                                                                              Use a Uniform Approach
                                                                              Monitor Success



                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                               87




                          Test Design before Deployment

                                              uBR7246vxr


                                                                                        Up Converter
                                                                                                                      Cable Modem

                                                                                        IF            RF
                                                       44Mhz        (downstream)                      52-750Mhz

                                                                                                  H
                                                                                             L             C
                                                     50-42Mhz           (upstream)
                                                                                             Di-Plex Filter       Splitter




                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                               88




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Combining Possibilities

                         You Can...

                             • Combine Multiple Rx Nodes to One Receiver
                                                                Called: Sparse Mode
                             • Combine Multiple Rx Node to Multiple Receivers
                                                              Called: Dense Mode
                             • Combine One Rx Node to Multiple Receivers
                                                              Called: WideBand Dense Mode


                                      (IP engineers may confuse these combining models with
                                      multicast sparse and dense modes. They are very different.)

                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                       89




                          Sparse Mode
                         CMTS

                                                                                        U0 = 20 MHz @ 1.6 MHz
                               DO
                        LC                                                                BW = 2.56 Mbps for
                        1x1 U0                                                             4 Serving Areas



                           Limited Bandwidth for Multiple Serving Areas

                           Over-Subscription a Concern

                           Collisions a possibility

                           Greatest Density

                           Be realistic about numbers of modems per linecard
                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                       90




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Dense Mode
                         CMTS
                                                                                        U0 = 20 MHz @ 1.6 MHz
                                                                                        U1 = 22 MHz @ 1.6 MHz
                            DO
                                                                                        U2 = 26 MHz @ 1.6 MHz
                        LC UO                                                           U3 = 28 MHz @ 1.6 MHz
                            U1
                        1x4 U2                                                           BW = 10.24 Mbps for 3
                            U3                                                               Serving Areas

                           Each US MUST be a different Frequency

                           Load Balance through provisioning

                           Easy way to add BW to a Serving Area

                           Need Open Upstream Ports


                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                             91




                          Extreme Dense Mode!
                         CMTS
                                                                                         U0 = 20 MHz @ 1.6 MHz
                                                                                        U1 = 22 MHz @ 1.6 MHz
                            DO
                                                                                        U2 = 26 MHz @ 1.6 MHz
                        LC UO                                                           U3 = 28 MHz @ 1.6 MHz
                            U1
                        1x4 U2                                                          BW = 10.24 Mbps for One
                            U3                                                                Serving Area!

                           Each US MUST be a different Frequency

                           Provisioning Assistance Speeds Bringup

                           Stop Gap before Node Split

                           Need Open Upstream Ports


                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                             92




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Combining Issues – Ingress!
                                                                                         OPTICAL TRANSMITTER
                                                                                               SPLITTER              #1
                                                                                                               500
                                                                             RF
                        uBR-MC16C                                        50-750 MHz                                  #2
                                                                                                               500
                                                                      Frequency F 1                                  500   #4
                            64 QAM
                            27 Mbs           TX 1                        Upconverter

                          6 MHz BW
                                               RX 1
                          44 MHz IF
                                                                                             FROM NODE # 1 (32 dB CNR)
                                               RX 2

                                               RX 3
                                                                                              FROM NODE # 2 (32 dB CNR)
                                                            SIGNAL FROM
                                               RX 4           4 NODES
                                                                                                FROM NODE # 3 (34 dB CNR)
                                                             3000 HOMES
                             QPSK                              PASSED
                            2.3 Mbs            RX 5

                                                                                             FROM NODE # 4 (35 dB CNR)
                            1.6 MHz            RX 6


                                                 ONE RECEIVER SUPPORTING 4 NODES (2000 HOMES PASSED)
                      SPL-230
                      3087_05_2001    © 2001, Cisco Systems, Inc. All rights reserved.                                     93




                          Watch the C/N


                                        • Determining aggregated C/N when
                                          combining nodes
                                        Example:
                                        • Determine aggregated C/N for
                                          upstream signals having C/N
                                          of 32 dB, 34 dB, and 35 dB
                                        • Total C/N = 27.04 dB


                      SPL-230
                      3087_05_2001    © 2001, Cisco Systems, Inc. All rights reserved.                                     94




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Combining Multiple Upstream Signals


                           Example
                       Consider four upstream signals having Carrier to Noise Ratios (C/N) as follows:
                       US # 1 32 dB                         US # 2 32 dB
                       US # 3 34 dB                         US # 4 35 dB

                       Combining CNR :
                       US # 1+ US # 2;                                   dB difference = 0 dB,dB Subtraction = 3.0 dB,       Total Noise1 is 29.0 dB

                       Total Noise1 + US # 3                             dB difference = 5 dB,dB Subtraction = 1.2 dB,       Total Noise2 is 27.8 dB

                       Total Noise2 + US # 4                             dB difference = 7.2 dB, dB Subtraction = 0.76 dB,    Total Noise3 is 27.04 dB


                       The aggregated noise of the four upstreams results in a C/N of 27.04 dB



                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                                             95




                          Combining issues – Bandwidth!
                            Make Sure the Reverse
                            Combining is Well                                                                 WOW, 3.58 MBps!
                            Thought Out
                                                                                              512 Kbps US
                                                                           512 Kbps US
                                                                                                            512 Kbps US
                                       CMTS


                                                                                                          512 Kbps US


                                                                         512 Kbps US                         512 Kbps US

                           Only 2.5 Mbps                                                        512 Kbps US
                       Available per upstream!




                                                    Cable Modem A
                                                                                                                    Cable Modem B
                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                                                             96




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Plan for Growth

                          Have enough Bandwidth for
                          your users
                                                                                              • A modem only has
                                                                                                one tx and one rx
                                                                                              • There is a media max
                                         CMTS
                                                                                                and an aggregate
                                                                                                max dictated by the
                                                                                        HFC     protocol and the
                                                                                                physical network

                                 4



                          Ahhh, that’s better
                             10 Mbps...                           Cable Modem A




                                                                                                Cable Modem B
                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                               97




                                                                              Case Studies




                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                               98




Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Case Study: Return Path Noise
                          and Planning


                             • Provider found that current bandwidth was over
                               utilized and service quality was suffering.
                             How does the provider avoid this issue?
                             Plan ahead for future offerings. Maintain space for
                               growth. Track customer demographics. Deploy
                               flexible combining process. Perform complete
                               and ongoing spectrum analysis.



                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.   99




                          Case Study: Narrowband Ingress


                                 • MSO had service interruptions every evening
                                   due to narrowband ingress. Local RF noise
                                   picked up by open taps in the plant.
                                 How could this have been avoided?
                                 Characterization of the return path over time
                                  using cable TV analyzer to identify and avoid
                                  problem spectra.
                                 (advanced CMTS with spectrum agility and a spectrum
                                   analysis or monitoring tool)



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                          Case Study:
                          Heterogeneous Combining


                            • Customer had nodes varying from 2000
                              to 370 homes passed.
                            Does this customer use sparse or
                             dense mode?
                            Customer required both forms of combining
                             to accommodate both legacy and recently
                             implemented fiber nodes.


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                          Case Study A


                           • Customer Used Demographics for 5000
                             New Subs per month
                           • More worried about “Next Customer” than
                             proper design
                           • Ignored RF importance
                           • Used Existing Backbone and simply added
                             Broadband Traffic

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Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
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                          Case Study A


                                                    CMTS x 4                             Backbone Design              CMTS x 4


                                     HFC                                                                                         HFC

                                                                                             1 Gbps
                                                        FE links



                                               CMTS x 4
                                                                                               GE
                                                                                               links
                                HFC                                                                        FE links
                                                                                                           Time of Day
                                                                                                           DHCP
                                                    FE links
                                                                                                           TFTP




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                          Case Study A
                            Issues:

                                     • Customer has 30,000 Customers per
                                       month coming on the network
                                     • Customer has no central management
                                       control
                                     • Ignored RF importance - Not Enough
                                       Frequency Available
                                     • GigE Backbone is saturated

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Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          Case Study B

                                     • Customer Deployed Over Large
                                       Geographic Area
                                     • WAN Bandwidth a major issue
                                     • No IP address Planning
                                     • Used NAT extensively
                                     • Each city One UBR and 2,500-3,500
                                       users per linecard

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                          Case Study B
                            Issues:

                           • Backhaul BW undersized - E1 for each City
                           • Lack of Real IP addresses - Single Class C
                           • NAT limits functionality - gaming,
                             etc. broken
                           • Over-subscription drives customer
                             dissatisfaction


                      SPL-230
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Copyright © 2001, Cisco Systems, Inc. All rights reserved. Printed in USA.
Presentation_ID.scr
                          You have the KEY!


                                                                                        PLANNING
                                                                                         is the
                                                                                          KEY
                                                     to a successful Data over
                                                         Cable Deployment!

                      SPL-230
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                                                                                   Questions?




                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.              108




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                                                     Deploying Cable
                                                   Access Infrastructures
                                                                                        Session SPL-230




                      SPL-230
                      3087_05_2001   © 2001, Cisco Systems, Inc. All rights reserved.                     109




                                                    Please Complete Your
                                                       Evaluation Form
                                                                                        Session SPL-230




                      SPL-230
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                      SPL-230
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