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DOCSIS 3.0 DS Planning & Bandwidth Management

DOCSIS 3.0 DS Planning & Bandwidth Management. John Downey, Consulting Network Engineer – CMTS BU. Agenda. Objectives Terms M-CMTS Adapters and connectivity, linecards, timing servers, e-qams, .. I-CMTS Optional Architectures Frequency Stacking Levels Frequency Placement

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DOCSIS 3.0 DS Planning & Bandwidth Management

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  1. DOCSIS 3.0 DS Planning & Bandwidth Management John Downey, Consulting Network Engineer – CMTS BU

  2. Agenda • Objectives • Terms • M-CMTS • Adapters and connectivity, linecards, timing servers, e-qams, .. • I-CMTS • Optional Architectures • Frequency Stacking Levels • Frequency Placement • Isolation Concerns

  3. DS Questions & Potential Concerns • Why it’s Needed • Competitive pressure, offering higher tiers of service, more customers signing up • Frequency Stacking Levels & Placement • What is the e-qam max output with four channels stacked • Do channels have to be contiguous? • Isolation Concerns • Applications w/ different service grps lead to overlaid networks • Signals destined for one node could “bleed” over to another • DS Frequency Expansion to 1 GHz • Amplifier upgrades are occurring now. It’s best to make the truck roll once, so think about diplex filters, spacing, taps, etc.

  4. 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

  5. DOCSIS 3.0 Terms • Local DS = CMTS DS • Remote DS = E-QAM DS • Primary = DOCSIS messaging • Secondary = Bonding • “Wideband” generically used to describe D3.0 DS bonding • Channel Grouping Domain (CGD) is MxN mac domain • Mac Domain = 1 DS & N USs • Service group = CMTS Fiber Node config • M-CMTS is an architecture, not necessarily D3.0 • Provides DS load balance within MxN domain • I-CMTS allows MxN and bonding within linecard • D3.0 CM supports minimum of 4 US and 4 DS chs • CMs on market are 4x4 (TI-based) & 8x4 (Brcm-based)

  6. DOCSIS 3.0 DS Ch Bonding over SPA Overview • Uses M-CMTS compliant Edge-QAM • Cisco RFGW-1D and RFGW-10 • Harmonic NSG-9000 • Increase legacy DS port density of uBR10K • Uses DTI timing source for DS channels • Enables legacy DOCSIS [1.x/2.0] CMs to use external QAMs for operation • Allows MxN mac domains • Eliminates need for PC from 5x20 card • Allows bonding on all channels in a BG • Hits the 100 Mbps BW mark on a 3-channel CM

  7. Narrowband Network Topology

  8. DOCSIS 3.0 DS Ch Bonding over SPA Requirements • CMTS • Cable linecard • US ports needed and host • DS bonding adapter • 1 Gbps fiber or copper ports • DTI timing card • DTI Server (Symetricom) • M-CMTS compliant EQAM • Cisco RFGW-1D or RFGW-10 • Harmonic NSG9000 • Arris • WCM300 (Linksys BroadLogic) • SA 3-Ch DPC 2505 (BCM 3381) • Cisco/SA DPC 3000 4x4 TI • Cisco/SA DPC 3010 8x4 Brcm

  9. DOCSIS 3.0 M-CMTS System DTI Server D3.0 DS + Primary Jacket Card DTI Card D3.0 BG DTI Card WB DS SPA M-CMTS EQAM WB DS SPA Primary Ch CPU/RP Primary MC5x20H SA DPC 3000 SA DPC-2505 CM CM CM CM Backhauls uBR10K CMTS NB DS

  10. Questions • Any rules-of-thumb to estimate service group size? • What recommendations are there for HE combining/splitting to avoid intrusive changes later? • Any impairments in HE or plant that will affect DOCSIS 3.0 more compared to earlier versions? • Isolation • Off-air Ingress • Attenuation • Freq assignments, spectrum allocation, plant limits • If small amount of extra BW needed, is it possible to split 4 chs from DS port to use 2 chs in one SG and other 2 in another SG?

  11. M-CMTS: 100 Mbps Tier & 2 Ch US Bonding • 5 DS frequencies • 1 I-DS • 4 M-DS • (5 Primary) • 2 US frequencies • 2 channel bonding

  12. M-CMTS = 100 Mbps Service Tier • 5 DS freqs • 2 US freqs Remote Bonding Remote Primary Local Bonding Local Primary 16-QAM 64-QAM 3.2 MHz 6.4 MHz • 5, 5x4 MAC domains with ATDMA & TDMA USs • E-qam overlaid for 2 nodes 70/2 = 35 connectors • 3 e-qam chassis with 6 modules each • 4 freqs * 35 = 140 QAMs = 6 SPAs = Spumoni & PRE4

  13. I-CMTS: 100 Mbps Tier & 2 Ch US Bonding • 4 DS frequencies (4 I-DS) • 2 US frequencies • 2 channel bonding

  14. I-CMTS = 100 Mbps Service Tier • 4 DS freqs • 2 US freqs Local Bonding Local Primary 16-QAM 64-QAM 3.2 MHz 6.4 MHz • 5, 4x4 MAC domains with ATDMA & TDMA USs • DS connector overlaid for 2 nodes, 35 connectors*2 = 70 nodes • 4 freqs * 35 = 140 QAMs = PRE4

  15. Cons Requires M-CMTS architecture Requires five DS & three US freqs Must push 3.0 CMs to remote DS Bonding group must be same IP bundle CM ranging overlap with “real” data? M-CMTS Overlay • Pros • Four bonding freqs / e-qam connector • Only 1 e-qam connector per 8 nodes • Basic = 2 DS/2 nodes with DCC support • US load balance of 2.0 CMs • One US connector shared across 2 nodes for diminishing D1.x CMs • 5 DS freqs • 3 US freqs • 2x5 domain Remote DSs Local DSs 3.2 MHz 6.4 MHz

  16. Cons Requires 8 DS & 3 US freqs I-CMTS with DS Overlay • Pros • 8 bonding freqs per 2 connectors • Only 5 connectors per 8 nodes • Can provide 8 ch DS bonding • US load balance of 2.0 CMs • One US connector shared across 2 nodes for diminishing D1.x CMs • 8 DS freqs • 3 US freqs • 5x5 domain Local DSs 3.2 MHz 6.4 MHz

  17. M-CMTS Wiring Diagram

  18. Cons Requires M-CMTS architecture Requires five DS & three US freqs Must push 3.0 CMs to remote DS Four e-qam connectors and 16 e-qam chs per 8 nodes M-CMTS Narrowcast • Pros • Four bonding freqs / e-qam connector • One e-qam connector per 2 nodes • Basic = 5 DS/2 nodes with DCC support • US load balance of 2.0 CMs • One US connector shared across 2 nodes for diminishing D1.x CMs • 5 DS freqs • 3 US freqs • 5x5 domain Remote DSs Local DSs 3.2 MHz 6.4 MHz

  19. DOCSIS 3.0 DS Considerations • Frequency assignments • CMTS may be limited to 860 MHz or 1 GHz • Legacy CMs (1.x & 2.0) limited to 860 MHz bandedge • E-qam limited to contiguous 24 MHz or 4 channel slots • 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 USs • Distance limitation, time offset differences, level differences • Resiliency is another topic to address • If one DS frequency goes bad in the field, how will CMs recover or react?

  20. DOCSIS 3.0 DS Considerations (cont) • E-qam licensing? • CM requires 1.1 config file • More DS = more US • Testing and maintaining multiple DS channels • Physical chs have not changed for DOCSIS 3.0 • Test equip with built-in CMs need to support bonding • DS ch bonding max power with 4 freqs stacked • Four chs stacked on 1 connector limited to 52 dBmV/ch • DOCSIS 1.x/2.0 DS is 61 dBmV max output • DS isolation issues

  21. 61? DS0 U0 U1U2 U3 1x4 Potential Isolation Path 1x4 DS1 U0 U1U2 U3 DS Combiner DS Splitter 1x4 DS2 U0 U1U2 U3 DS Tx 1x4 DS3 U0 U1U2 U3 52? Edge-QAM DS Ports with Edge-QAM for DS Bonding DSs 0-3 = 603 MHz E-QAM = 609, 615, 621, & 627 MHz • Requires: • 5 DS freqs • 3 US freqs in each node Isolation amp

  22. W Isolation Amp • Can this device handle 50 dBmV inputs?

  23. Design Rules & Restrictions • D3.0 spec goes to 1 GHz, some equipment may not • SA DPC2505 speced to 930 MHz • DPC2505, 3 ch CM needs all 3 DSs for 111 Mbps • Can do annex B &/or A; but requires more spectrum • D3.0 CM spec requires 60 MHz capture window • DPC3000 capture of 96 MHz over most spectrum • 82 MHz max window supported over entire spectrum • TI 4x4 CM (60 MHz window) • Brcm 8x4 CM (2, 32 MHz bands or 1, 96 MHz band) • DS freqs must be contiguous within tuner block unlike 4x4 CMs • Can use RCC templates to setup both tuners • New feature called Split Tuner will analyze RCC & create 2 Rx modules and move tuners automatically without RCC templates

  24. Modem Steering • Restrict legacy eMTAs to Local DS • Enforce legacy CMs to only register on Primary-only DS • Enforce legacy CMs to move to specific DS freq • Force 3.0-capable CMs to initialize on bonding capable primary DS • Can specify UCDs sent for each DS • Put voice call service flows on a primary DS • cable docsis30-voice downstream req-attr-mask 0 forb-attr-mask 80000000 • EDCS-668028 explains this feature

  25. Node Splitting DS0 U0 U1U2 U3 1x4 Edge-QAM • 2x4 domain appears as 2, 1x2 domains

  26. Summary • Cost effective and faster time to market • Decrease DS costs – deploy D3.0 later with no additional CMTS investment! • Targeted insertion of D3.0 • Leverage existing US chs while adding more DS 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

  27. 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 • Can also disable DS bonding • No cable mrc-mode • Per-CM exclude with vendor specific MIB or TLV

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