Planning for DOCSIS 3.0 NOW!Brady VolpeJDSUJDSU

John DownyyCisco Systems

Webcast, Tuesday, December 9, 2009

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A dAgenda

Part I: DowneyDOCSIS 2 0 U t DOCSIS 2.0 Upstream

DOCSIS 3.0 DownstreamDOCSIS 3 0 Upstream DOCSIS 3.0 Upstream

Part 2: VolpeDOCSIS 3 0 Downstream DOCSIS 3.0 Downstream

DOCSIS 3.0 Upstream Node Analysis Node Analysis Live and Historical Analysis

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Planning for DOCSIS 3 0 Planning for DOCSIS 3.0 NOW!

John J. Downey yCisco

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AgendaAgenda DOCSIS 2 0 US Considerations DOCSIS 2.0 US Considerations

64-QAM at 6.4 MHz (levels, profiles, frequency allocation) Linear Impairments (group delay, micro-reflections) Laser Clipping Monitoring, Testing & Troubleshooting

DOCSIS 3 0 DS Considerations DOCSIS 3.0 DS Considerations Frequency Stacking Levels & Placement Isolation Concerns

DOCSIS 3.0 US Considerations Frequency Stacking Levels (max output, pwr/Hz, laser clipping) Diplex Filter Expansion to 85 MHz? Diplex Filter Expansion to 85 MHz?

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B i Obj tiBusiness Objectives

Allow more BW for DOCSIS 1.x & 2.0 CMs

Limit/reduce more node splits Limit/reduce more node splits

Introduce new HSD service of 50 to 100Introduce new HSD service of 50 to 100 Mbps

Allow migration of existing customers to higher tier and DOCSIS 3 0 capabilityhigher tier and DOCSIS 3.0 capability Better Stat Muxing

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ATDMA DeploymentATDMA DeploymentRecommendations

Aft i i CW t 6 4 MH & d t After increasing CW to 6.4 MHz, measure & document unequalized US MER at multiple test points in the plant

Use PathTrak Return Path Monitoring System linecard Use PathTrak Return Path Monitoring System linecard Or Sunrise Telecom Upstream Characterization toolkit

25 dB hi h U li d MER i d d 25 dB or higher Unequalized MER is recommended Less than 25 dB reduces operating margin

Check US MER as ell as per CM MER Check US MER as well as per-CM MER

Make sure latest IOS version is running on CMTS

Pick freq < 30 MHz away from diplex filter group delay

Turn on Pre-Equalization

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q

US MER(SNR) Issues Increasing ch width from 3 2 to 6 4 keeps same averageIncreasing ch width from 3.2 to 6.4 keeps same average

power for single carrier SNR drops by 3 dB or morey

Keeping same power/Hz could cause max Tx level from CMs and/or laser clipping/overloadpp g

Equalized vs unequalized MER readings

M d l ti fil h i Modulation profile choices QPSK for maintenance, 64-QAM for Data, 16-QAM for VoIP?

Pre-EQ affect Great feature in 1.1 & > CMs, but could mask issues

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Post Deployment Monitoring MetricsC t bl FEC (US & CM) E li d/PRE EQ MER(SNR) (US Correctable FEC (US & per-CM) If > 2.5 %: minor alarm If > 5 %: major alarm

Equalized/PRE-EQ MER(SNR) (US & per-CM) If < 27 dB: minor alarm

Uncorrectable FEC (US & per-CM) If > 0.1 %: minor alarm

If > 1 %: major alarm

If < 24 dB: major alarm

Cable Flap-List (D3.0 Modem Diagnostic Log) If > 1 %: major alarm Diagnostic Log)

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Post Deployment TroubleshootingPost-Deployment Troubleshooting MER per US with ability to drill down for per CM MER MER per US with ability to drill-down for per-CM MER

Use Return Path monitoring tools like Cisco Broadband Troubleshooter (CBT) or PathTrak to view 5-65 MHz for apparent laser ( ) ppclipping Need analyzer to read < 5 MHz for AM or ham radio ingress

New PathTrak card reads 0 5 MHz 85 MHz New PathTrak card reads 0.5 MHz - 85 MHz

Cable Flap-List monitoring for US or CM issues

Uncorrectable /Correctable FEC per US with ability to drill down for Uncorrectable /Correctable FEC per US with ability to drill-down for per-CM counters

Bottom line is correctable & uncorrectable FECBottom line is correctable & uncorrectable FEC If correctable FEC is incrementing, then eventually it will lead to

uncorrectable FEC, which equals packet drops

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Flap-List Monitoring Recommendationsbl fl li t i th h ld 5 cable flap-list miss-threshold 5

Count increments by 1 if 5 consecutive polling misses (5, T3s)

cable flap-list power-adjust threshold 2cable flap list power adjust threshold 2 Count increments by 1 if CM has power adjustment of 2 dB or

higher during one station maintenance interval

cable flap-list insertion-time 120 Count increments by 1 if CM sends initial ranging 2 or more times

within 2 minutes

Periodically poll flap-list at an appropriate interval (every 30 minutes or so)

Perform trend analysis to identify CMs that are consistently in flap-list

Query billing and administrative database for CM MAC address-to-street address translation & generate report

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street address translation & generate report

CMs in specific area with lots of flaps can indicate faulty amp or feeder lines

DOCSIS 3 0DOCSIS 3.0 TermsTerms

Local DS = CMTS DS Remote DS = E-QAM DS Primary = DOCSIS messaging Secondary = Bonding

C bi G D i (CGD) i M N d i Combiner Group Domain (CGD) is MxN mac domain Mac Domain = 1 DS & N USs

D3 0 CM supports a minimum of 4 US and 4 DS channels D3.0 CM supports a minimum of 4 US and 4 DS channels

Wideband is generically used to describe D3.0 DS bonding

M CMTS i hit t t il D3 0 M-CMTS is an architecture, not necessarily D3.0 Provides DS load balance within MxN domain

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DOCSIS 3 0 Potential OptionDOCSIS 3.0 Potential Option

5 DS fRemote

DSs

5 DS freqs 3 US freqs 2x5 domain

LocalDSs

3.2 MHz

6.4 MHz

ProsFo r bonding freqs / e qam connector C Four bonding freqs / e-qam connector

Only 1 e-qam connector per 8 nodes Basic = 2 DS/2 nodes with DCC support

Cons Require M-CMTS architecture Must push 3.0 CMs to remote

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US load balance of 2.0 CMsp

DS

DOCSIS 3 0 DS IDOCSIS 3.0 DS Issues Frequency assignmentsFrequency assignments

CMTS may be limited to 860 MHz or 1 GHz E-qam limited to contiguous 24 MHz or 4 channel slots

Annex A may only be 3 chs vs 4 for annex B Annex A may only be 3 chs vs 4 for annex B CMs may be limited to 50 or 60 MHz passband

M-CMTS architecture requires DTI and local USsC S a c tectu e equ es a d oca USs Distance limitation, time offset differences, level differences

How to deal with freq stacked DSs if not using them all?

DS isolation issues

DS ch bonding max power with 4 freqs stackedg p q Four chs stacked on one connector limited to 52 dBmV/ch

DOCSIS 1.x/2.0 DS is 61 dBmV max output

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DS P t ith Ed QAM f DS B diDS Ports with Edge-QAM for DS BondingDSs 0 3 = 603 MHz

DS01x4

61?DSs 0-3 = 603 MHzE-QAM = 609, 615,

621, & 627 MHzU0U1U2U3

1x4

DS Combiner

DS1

U0U1U2

1x4 Potential Isolation Path

DS Combiner

DS Splitter

U3

DS2

U0U1

1x4

DS TxU1U2U3

DS31x4Requires: 5 DS freqs 3 US freqs in each node

U0U1U2U3

I l ti

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Isolation amp

Design Rules and RestrictionsDesign Rules and Restrictions D3 0 spec goes to 1050 MHz but some equipment may not D3.0 spec goes to 1050 MHz, but some equipment may not

SA DPC2505 speced to 930 MHz

DPC2505 3 h CM d ll 3 DS f 111 Mb DPC2505, 3 ch CM needs all 3 DSs for 111 Mbps Can do annex B &/or annex A chs, but requires more

spectrumspectrum

What about resiliency? If 1 DS freq goes bad in field how will CMs recover or If 1 DS freq goes bad in field how will CMs recover or

react?

Directing CMsDirecting CMs Restrict legacy eMTAs to Local DS & enforce legacy

CMs to only register on Local DS or move to a specific

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DS frequency Force 3.0-capable CMs to initialize on remote/e-qam DS

Four ch limitation for bonding and only on e qam

US IUS Issues Freq assignments: 5 to 42, 55, 65, 85 MHz?Freq assignments: 5 to 42, 55, 65, 85 MHz? Diplex filters, line EQs, step attenuators, CPE overload Max Tx for D2.0 64-QAM for 1 ch is 54 dBmV

D3.0 US ch max power Tx for D3.0 TDMA

17 - 57 dBmV (32 & 64-QAM) 58 dBmV (8 & 16-QAM) 61 dBmV (QPSK)

Tx for D3.0 S-CDMA17 56 dB V ( ll d l ti ) 17 - 56 dBmV (all modulations)

Max Tx per ch for 4 freqs stacked at 64-QAM ATDMA is onl 51 dBmV & 53 for S CDMA

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only 51 dBmV & 53 for S-CDMA

US I t SUS Input Spec

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US Load Balance & Isolation Example

4-WayCMTS US0@ 24 MHz

Fiber OpticRx 1

CMTS US2

Filter

4 Way

CMTS US2@ 31 MHz

Fiber OpticRx 2

Amplifier

4-WayCMTS US1@ 24 MHz

Attempting to share one US port across two other US ports Can cause isolation issues

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Load balance issues (ambiguous grouping)

System Levels Reverse 17 dB at 5 MHz & 32 dB at 1 GHz

4

CS(CEQ) tap

17 dB at 5 MHz & 32 dB at 1 GHz Eliminates max transmit CMs Eliminates high DS tilt to TV

FEQ

26 23 17 4350 500 6001.5 dB 2 2.5

w/ US pad

Step Attenuator

17Input or EQ tap

43 dBmV 42 39.5 29Reversetransmitl l @ th t

38X

PIII .5 cable.40 dB @ 30 MHz

level @ the tap

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A total design variation of ~14 dB!

Questions?Questions?Brady Volpe

Director Systems Engineering and Design Verification, JDSU

John DownyBroadband Network Engineer Cisco SystemsBroadband Network Engineer, Cisco Systems

Th k f tt diThanks for attending: Planning for DOCSIS 3 0 -- Now!

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Planning for DOCSIS 3.0 Now!

DOCSIS 3.0 Trade-OffsR hl f ti i d DS / US d t th h t Roughly four times increased DS / US data throughput

Accomplished via channel bonding occupying four times theAccomplished via channel bonding occupying four times the bandwidth of D1.x and D2.x systems

Four times the DS DOCSIS QAMs quadruples the probability for impairments on the subscriber premprobability for impairments on the subscriber prem.

Four times the US bandwidth (four bonded channels) creates a new dynamic for troubleshooting andcreates a new dynamic for troubleshooting and monitoring: Increased likelihood for laser clipping

I d b bilit f bl ith i d l Increased probability for problems with ingress, group delay, micro-reflections, and other linear distortions

Inability to avoid problem frequencies such as Citizens Band,

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Ham, Shortwave, and hop between CPD 6MHz spacing Where are you going to put your sweep points?Plant maintenance and monitoring has never been more critical!Plant maintenance and monitoring has never been more critical!

Analyze Multiple D3.0 Downstreams Bonded downstream

channels increase the b bilit f i i tprobability of impairments

Diagnose each DOCSIS downstream as a QAMdownstream as a QAM channel, measure: LevelLevel MER Pre- & Post-FEC

DSAM Family

Divide and conquer the network back to the node

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HFC Network Certification Installation & Maintenance

Typical MER RequirementsA DOCSIS compliant network must have < 10-8 post-FEC errors (BER)A DOCSIS compliant network must have < 10-8 post-FEC errors (BER)

64-QAM 256-QAMBER MER MER Quality

10-10 >35 >35 Excellent

10-8 27-34 31-34 Good

10-6 23-26 28-30 Marginal10 23 26 28 30 Marginal

10-5

A idi CPD Si l US ChAvoiding CPD Single US Ch.Locate

DOCSIS Ch. here while

Locate DOCSIS Ch. here while

resolving CPDresolving CPD

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Avoiding CPD - Multiple Upstreams

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US Un-Equalized MER

Divide & conquer qupstream linear impairments withimpairments with upstream unequalized MERunequalized MER in DSAM

DSAM Family

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HFC Network Certification Installation & Maintenance

Upstream Transmit Power in D3.0

Max transmit power per channel varies with number of channels in the Transmit Channel Set

Single Channel in Transmit Channel Set or with gMultiple Transmit Channel mode disabled Max transmit power raised 3 dB from DOCSIS 2.0 p

levels Min transmit power raised from DOCSIS 2.0 p

levels Dependent on symbol rate

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p y Lowest transmit level is +17 dBmV(up from +8 dBmV)

Upstream Transmit Power in D3.0

Large dynamic range to addressrange to address

Modulation, number of active u be o act eupstream channels and presence of D2.0 modemsR lt P t ti l Result > Potential upstream Laser clipping

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clipping

Look for Laser Clipping Out to 85 MHz

Wide band impulse noise above diplexabove diplex roll-off frequency

Four (4) 16QAMDOCSIS carriers

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42 MHz diplex filter roll-off frequency

PathTrak QAM Analyzer ViewGood NodeGood Node

MER & LevelAvg/Max/Min

QPSK to 64QAM ConstellationsConstellations

Li MER L l &Live MER, Level & Symbol Count

MER & Level Graphed over Time

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PathTrak QAM Analyzer ViewBad NodeBad Node

Interference easily visible in 16 QAM

constellation

Interference easily visible in 16 QAM

constellation

Interference easily visible in 16 QAM

constellationconstellationconstellationconstellation

Interference causing gintermittent low MER

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Live Spectrum (DOCSIS) Analysis Live spectrum view of analog and QAM RF

icarriers

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Live QAM (DOCSIS) Constellation

Live view of 256QAM

constellation

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Live QAM Level, MER and Pre/Post BERLive view of RF level

measurements graphed over timeg p

Live view of MERLive view of MER measurements

graphed over time

Live view of Pre/Post BER measurements

graphed over time

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Historical QAM LevelHistorical QAM Level,MER and Pre/Post BER

Historical view of RF level

measurements graphed over

time

Historical view of MER

measurements h dgraphed over time

Historical view of Pre/Post FEC BER

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Historical view of Pre/Post FEC BER measurements graphed over time

Summary DOCSIS 3.0 offers tremendous data throughput

increases

With this comes challenges in further evolving the HFC plant to support the physical layerplant to support the physical layer

Preventative maintenance and plant monitoring must bePreventative maintenance and plant monitoring must be implemented to ensure quality for HSD and VoIP subscribers

Planning for DOCSIS 3.0 now is imperative in order for successful future deployments

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successful future deployments

Modulation Error Ratio (MER)Th lit f QAM The quality of a QAM signal can be measured by MERy

The tighter the cluster of symbols, th b tt th i lthe better the signal and higher the MER number in dB

Impairments spread out the cluster and lower the MERlower the MER number

( )

= Nav

symbEdBMER 10log10

www.cable360.net/ct 37 MER is the ratio in dB between the

average power of the signal and the power of the error vectors 37

( )

=

N

jj

symb

eN 1

210 1g