© 2009 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID 1 DOCSIS 3.0 US Planning & Bandwidth Management John Downey, Consulting Network Engineer – CMTS BU

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 2 Presentation_ID Co-Sponsor – CCI Systems  Cisco Gold Partner  End-to-end network services –Network and headend engineering –Network mapping –Network construction (cable/fiber) –Network maintenance –NOC services

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 3 Presentation_ID Co-Sponsor – Todd Gingrass, CCI Systems  Vice President of Network Technology  14 years at CCI Systems.  Bachelor of Electrical Engineering degree from Michigan Technical University  Certifications include Cisco Certified Network Associate Routing & Switching (CCNA), Cisco Certified Design Associate (CCDA), and Cisco Certified Internetwork Professional (CCIP)  A member of the Society of Cable and Television Engineers (SCTE) and Institute of Electrical and Electronics Engineers (IEEE)

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 4 Presentation_ID Presenter – John Downey, Cisco  20 years in the data/telecommunications/ networking industry  BS in Electrical Engineering from Penn State University.  Nine years with Cisco as a Broadband Network Engineer presently with the Cable Modem Termination System (CMTS) Business Unit.  Certifications include CCNA and CCCS.  An SCTE member since ’96.

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 5 Presentation_ID Agenda  Frequency Stacking Levels –What is CM max US output with four channels stacked and do channels have to be contiguous?  Power/Hz & laser clipping  Diplex Filter Expansion to 85 MHz? –Amplifier upgrades occurring now; Best to make 1 truck roll –Think about diplex filters, line EQs, step attenuators, taps, etc.

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 6 Presentation_ID Business Objectives  Allow more BW for DOCSIS 1.x & 2.0 CMs  Limit/reduce more node splits  Introduce new HSD service of 50 to 100 Mbps  Allow migration of existing customers to higher tier and DOCSIS 3.0 capability –Better Stat Muxing

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 7 Presentation_ID ATDMA General Deployment Recommendations  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 –Or Sunrise Telecom Upstream Characterization toolkit  25 dB or higher Unequalized MER is recommended –Less than 25 dB reduces operating margin –Check US MER as well as per-CM MER  Pick freq < 30 MHz away from diplex filter group delay  Make sure latest IOS version is running on CMTS  Turn on Pre-Equalization

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 8 Presentation_ID US MER(SNR) Issues  Increasing ch width from 3.2 to 6.4 keeps same average power for single carrier –SNR drops by 3 dB or more  Keeping same power/Hz could cause max Tx level from CMs and/or laser clipping/overload  Equalized vs unequalized MER readings  Modulation profile choices –QPSK for maintenance, 64-QAM for Data, 16-QAM for VoIP? –Max output for 64-QAM is 54 dBmV Cab up n power-adjust continue 6  Pre-EQ affect –Great feature in 1.1 & > CMs, but could mask issues

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 9 Presentation_ID Post-Deployment Monitoring Metrics  Correctable FEC (US & per-CM) –If > 2.5 %: minor alarm –If > 5 %: major alarm  Uncorrectable FEC (US & per-CM) –If > 0.1 %: minor alarm –If > 1 %: major alarm  Equalized/PRE-EQ MER(SNR) (US & per-CM) –If < 27 dB: minor alarm –If < 24 dB: major alarm  Cable Flap-List –D3.0 Modem Diagnostic Log –Can utilize IPDR

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 10 Presentation_ID Post-Deployment Troubleshooting  MER per US with ability to drill-down for per-CM MER  Use Return Path monitoring tools –Cisco Broadband Troubleshooter (CBT) –Need analyzer to read < 5 MHz for AM or ham radio ingress –PathTrak to view 5-65 MHz for apparent laser clipping 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 per-CM counters  Bottom line is correctable & uncorrectable FEC –If correctable FEC is incrementing, then eventually it will lead to uncorrectable FEC, which equals packet drops

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 11 Presentation_ID D3.0 US Issues  Frequency Stacking Levels –What is the max output with multiple channels stacked –Is it pwr/Hz & could it cause laser clipping?  Diplex Filter Expansion to 85 MHz –If amplifier upgrades are planned for 1 GHz, then pluggable diplex filters may be warranted to expand to 85 MHz on the US –Still must address existing CPE equipment in the field and potential overload –RFoG could be perfect scenario (maybe even 200 MHz split)  CM must be w-online (requires 1.1 cm file) for US bonding  Monitoring, Testing, & Troubleshooting –Just like DOCSIS 2.0, now test equipment needs to have D3.0 capabilities

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 12 Presentation_ID US Frequency and Level Issues  Freq assignments –5 to 42, 55, 65, 85 MHz ? Diplex filters, line EQs, step attenuators, CPE overload  Max Tx for D QAM for 1 ch is 54 dBmV  D3.0 US ch max power –Tx for D3.0 TDMA dBmV (32 & 64-QAM) 58 dBmV (8 & 16-QAM) 61 dBmV (QPSK) –Tx for D3.0 S-CDMA dBmV (all modulations)  Max Tx per ch for 4 freqs stacked at 64-QAM ATDMA is only 51 dBmV & 53 for S-CDMA

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 13 Presentation_ID US Input Spec

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 14 Presentation_ID Total Power  Was only one US channel present, now up to four US chs transmitting at same time –Possibly 6.4 MHz each; nearly 26 MHz US channel loading  Lots of power hitting return path fiber optic transmitter  Probability of laser clipping is increased, especially if using legacy Fabry-Perot (FP) lasers –Good idea to upgrade to Distributed Feedback (DFB) lasers, which have significantly more dynamic range  Use return path monitoring system capable of looking above 42 MHz to see second and third order harmonics  Any burst noise above diplex filter (i.e. 42 MHz) coming out of return path receiver is usually indicative of laser clipping

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 15 Presentation_ID Laser Clipping  Blue trace shows case of strong laser clipping  Green line represents flat US laser noise floor with no clipping  Note that this US has four US bonded channels

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 16 Presentation_ID Channel Placement  Each US channel used for bonding is individual channel  Transmitters (channels) are separate –Don't have to be contiguous and can have different physical layer attributes like; modulation, channel width, tdma or scdma, etc.  Frequencies can be anywhere in US passband and do not need to be contiguous  It may be wise to keep relatively close so plant problems like attenuation and tilt don’t cause issues  CM will have some dynamic range to allow specific channels to be a few dB different vs. other channels

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 17 Presentation_ID New Architectures  New conundrum raised when fiber run deeper into network –RF over Glass (RFoG) –DOCSIS Passive Optical Networks (DPON)  May incorporate 32-way optical splitter/combiners. Having a laser Tx in your house combined with 32 other houses feeding 1 Rx in the HE is addressed with lasers timed with the actual traffic from the house; unlike how it is done today where the US laser is on all the time  US bonding and/or load balancing presents potential issue where an US laser could be transmitting same time as another US laser  May be acceptable with multiple lasers transmitting same instant in time, if they are carrying different frequencies,  Will S-CDMA pose same problems? This multiplexing scheme allows multiple CMs to transmit same instant in time

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 18 Presentation_ID US Load Balance & Isolation Example  Attempting to “share” one US port across two other US ports –Can cause isolation issues –Load balance issues (ambiguous grouping) 4-Way CMTS 24 MHz CMTS 24 MHz CMTS 31 MHz Fiber Optic Rx 1 Fiber Optic Rx 2 Filter Amplifier

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 19 Presentation_ID System Levels Reverse ’ 500’600’ 1.5 dB Input 43 dBmV PIII.5” cable MHz Reverse transmit the tap A total design variation of ~14 dB! CS(CEQ) tap 17 dB at 5 MHz & 32 dB at 1 GHz Eliminates max transmit CMs Eliminates high DS tilt to TV FEQ w/ US pad Step Attenuator or EQ tap 38 X

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 20 Presentation_ID Transmit Level Possibilities  Running D3.0 CM in low modulation scheme allows higher power  Use D3.0 CM in 2.0 mode –Single frequency on D3.0 CM offers 3 dB higher power  Using SCDMA with more codes may also allow higher Tx power, but depends on implementation  Minimum level of 17 dBmV (24?) could cause issues in lab environment or HE test CM –Pmin = +17 dBmV, 1280 ksym/s –Pmin = +20 dBmV, 2560 ksym/s –Pmin = +23 dBmV, 5120 ksym/s

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 21 Presentation_ID Summary  Cost effective and faster time to market –Decrease costs today – deploy DOCSIS 3.0 later with no additional CMTS investment!  Targeted insertion of D3.0 –Leverage existing US chs while adding more US capacity –Load balance 1.x/2.0 and enable D3.0 when needed –Minimizes capex & opex  Leverage D3.0 bonding for D2.0 tiers & services –Better stat-mux efficiency –Improved consumer experience

© 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential 22 Presentation_ID Summary (cont)  Long term D3.0 service planning –Insure optimized frequency allocation –Enable seamless upgrade to higher D3.0 tiers –Wire once –Add QAM chs as tiers or service take-rates go up  End-to-end solution minimizes risk –CMTS, QAM, and CPE  Account for physical connectivity, not just channel capacity –May not be advantageous to combine noise to satisfy connectivity