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Vectoring De-mystified

Vectoring De-mystified. Market Drivers Understanding Vectoring Vectoring Described Benefits of System-Level Implementation. National Goals by 2020: Ubiquitous 100Mbps Broadband. Germany: 100Mbps to 50% of subscribers. France: 100Mbps to 70% of subscribers. US:

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Vectoring De-mystified

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  1. Vectoring De-mystified • Market Drivers • Understanding Vectoring • Vectoring Described • Benefits of System-Level Implementation

  2. National Goals by 2020:Ubiquitous 100Mbps Broadband • Germany: • 100Mbps to 50% of subscribers • France: • 100Mbps to 70% of subscribers • US: • 100Mbps to 100 Million households • Reaching 2020 Goal is of National and Global Importance • Australia: • 100 Mbps to 90% households

  3. It impacts a country’s well being “Savings in the health sector …to fall between 1.4% and 3.7% as a direct result of having the new network in place.” ITU National Broadband Plan Recommendations “… 10 percent increase in broadband penetration …1.3 percent additional growth GDP.” ITU National Broadband Plan Recommendations

  4. And Drives Business Success Higher bandwidth results in more exciting applications which leads to increased adoption and higher revenue per user Launched in the last 6 years Super connected subscribers will lead to new industries and companies we can’t even imagine yet

  5. 100Mbps+ Downstream: 25x faster than today’s average • A complete album in 5 sec • An Entire HD movie in less than 10 min • 4Mbyte photo in 1/3 second • Cloud based Multi-screen 3D Gaming. • Multi-angle 3D HDTV

  6. 100Mbps: A Key Service Offering • 100Mbps services will be mainstream by 2015

  7. 100Mbps: A Key Service Offering • Numerous national and regional broadband plans give 100Mbps as a targeted speed • Cable operators are able to offer a 100Mbps tier with DOCSIS 3.0

  8. Can Wireline Service Providers Compete? • FTTH is the ultimate goal but still cost-prohibitive in many deployment scenarios • Telcos can be competitive with copper – 100Mbps is practical and economical with VDSL2 vectoring and bonding • Let’s see how…

  9. Vectoring De-mystified • Market Drivers • Understanding Vectoring • Vectoring Described • Benefits of System-Level Implementation

  10. VDSL2 Fundamentals - Discrete Multi-Tone • DMT Line Code Is Made Up of Individual Sinusoidal Carriers Whose Amplitude and Phase Change to Signal the Data Bits • The VDSL2 (G.993.2 ) Has Tone Spacing of 4.3125 kHz • 8.625 kHz for Profile 30a. • The Upstream Spectrum is Separated From Downstream. This Type of Segregation is Frequency Division Duplexing (FDD)

  11. DMT Tone Modulation • These figures illustrate the real and imaginary QAM amplitudes for 2, 3 & 4 bit tone modulations on each tone. • Each tone carries some number of bits (1≤ bits ≤ 15) based on its signal-to-noise ratio (SNR). Three bits Two bits Four bits

  12. NEXT Coupling DSL1 DSL1 DSL2 DSL2 FEXT Coupling DSL1 DSL1 DSL2 DSL2 What Is Crosstalk?

  13. ANSI Crosstalk Noise Models

  14. How Many Bits On Each Tone? • The Number of Bits Carried on Each Tone is Determined by The Effective Signal to Noise Ratio (SNR) Around That Tone. • The Greater the SNR, the More Bits Carried on the Tone SNR

  15. ADSL2+ 11 Bit Constellation

  16. What is Vectoring? -FEXT +FEXT +FEXT +FEXT -FEXT +FEXT +FEXT -FEXT +FEXT

  17. G.Vector ITU Recommendation G.993.5 Vectoring

  18. Why Vector Profile 17 Instead of Using Profile 30?

  19. Why Vector Profile 17 Instead of Profile 30?

  20. Vectoring De-mystified • Market Drivers • Understanding Vectoring • Vectoring Described • Benefits of System-Level Implementation

  21. Vectoring Modifications to Startup O-P VECTOR 1 allows existing vectored pairs to learn FEXT couplings from the new line O-P Vector 1 composed of pilot modulated sync symbols & quiet symbols Special Operations Channel (SOC) Active New Line Error Feedback

  22. Aligned Synch Symbols Enable Training Downstream Ports DMT 3 DMT 3 DMT 3 DMT 3 DMT 3 DMT 3 Up Synch 4 DMT 4 Up Synch 4 Up Synch 4 DMT 4 Up Synch 4 DMT 4 Down Synch 1 Down Synch 1 DMT 1 DMT 1 DMT 1 Down Synch 1 Down Synch 1 DMT 2 DMT 2 DMT 2 DMT 2 DMT 2 DMT 2 time time time time time time time time Upstream Ports New Port

  23. Estimating the Crosstalk. The CPE reports the slicer error measured on the synch symbols and sends it back to the DSLAM

  24. DSL Transceivers DSL Transceiver Framer Encoder Modulator DSL Transceiver Framer Encoder Modulator DSL Transceiver Framer Encoder Modulator DSL Transceiver Framer Encoder Modulator

  25. G.993.5: G.vector Framer Encoder Modulator Precoder Framer Encoder Modulator Precoder Framer Encoder Modulator Precoder Framer Encoder Modulator Precoder Vector Control Entity

  26. G.993.5: G.vector DSL Modem Framer Encoder Modulator Framer Encoder Modulator Precoder Precoder DSL Modem Framer Encoder Modulator Framer Encoder Modulator Precoder Precoder DSL Modem DSL Modem Framer Encoder Modulator Framer Encoder Modulator Precoder Precoder Framer Encoder Modulator Framer Encoder Modulator Precoder Precoder Vector Control Entity Vector Control Entity

  27. G.vector: Vector Control Entity (VCE) DSL Modem Framer Encoder Precoder Modulator DSL Modem Framer Encoder Precoder Modulator DSL Modem Framer Encoder Precoder Modulator DSL Modem Framer Encoder Precoder Modulator Vector Control Entity • Vector Control Entity (VCE): • coordinates initialization of DSL links: orderly join/leave process

  28. G.Vector Steady State Operation DSL Modem Encoder Data Data Data Data Data Data Data Data Data Sync Sync Sync Data Data Data Data Data Data Data Data Data Framer Encoder Precoder Modulator DSL Modem Framer Encoder Precoder Modulator Encoder DSL Modem Framer Encoder Precoder Modulator Encoder Vector Control Entity • VCE: • Synchronizes timing and aligns “sync” symbols on DSL links • VCE instructs encoders to transmit probing signal during sync symbols • Modems send error signals to VCE • VCE updates coefficients for precoders

  29. G.vector: Adding a Line DSL Modem Encoder Data Data Data Data Data Data Data Data Data Sync Sync Sync Data Data Data Data Data Data Data Data Data Framer Encoder Precoder Modulator DSL Modem Framer Encoder Precoder Modulator Encoder DSL Modem Encoder Framer Encoder Precoder Modulator JoiningModem DSL Modem Framer Encoder Precoder Modulator Data Data Data Sync Data Data Data Encoder Vector Control Entity • VCE instructs encoder for joining modem to be silent during data symbols • Instructs all encoders to transmit probing signals during sync symbols • Modems send error signals to VCE • VCE learns crosstalk couplings from joining modem, updates coefficients for precoders • Joining modem can now send data

  30. DSP 1 DSP 2 DSP 4 DSP 3 Board Level FEXT Cancellation (across DSPs and VCE) Cable Plant

  31. Background on Binders Binder 1 New line cards or additional systems added Binder 3 Binder 2 No 1 to 1 correlation between systems and binders

  32. The Problem with VectoringSome Pairs Cannot be part of the Team Pairs in the same binder need to be handled as a single group to effectively implement vectoring Crosstalk(FEXT)

  33. Deployment Strategy – FEXT Cancellation = Binder Management

  34. Measured Results: Downstream Cable Vectoring: 48 lines (24L (rates shown) + 24R) in one vector group 12 13 13 12 Binder Vectoring: 24 (Left) Vectored + 24 (Right) unvectored

  35. Measured Results: Upstream Cable Vectoring: 48 lines (24L (rates shown) + 24R) in one vector group 12 13 13 12 Binder Vectoring: 24 (Left) Vectored + 24 (Right) unvectored

  36. Vectoring De-mystified • Market Drivers • Understanding Vectoring • Crosstalk, Bonding and Binder Management • Vectoring Described • Benefits of System-Level Implementation

  37. DSP 1 DSP 1 DSP 1 DSP 2 DSP 2 DSP 2 Cable Plant Cable Plant Cable Plant DSP 4 DSP 4 DSP 4 DSP 3 DSP 3 DSP 3 System Level FEXT Cancellation

  38. The Solution is a System ApproachLetting Everyone Join the Team Multiple OSP DSLAMs or Chassis Cards need to work together as a “system” so that vectoring can be performed across line cards or other OSP DSLAMs Crosstalk(FEXT)

  39. Board Level to System Level Upgradeability 1 Cards = 48 Ports Card 1 DSL Modem Binder Card 2 DSL Modem 2 Cards = 96 Ports Resource Card 3 Card 4 DSL Modem 3 Cards = 144 Ports 4 Cards = 192 Ports

  40. OSP Board Level to System Level Upgradeability Initially Single OSP has internal BLV DSL Modem Binder DSL Modem DSL Modem DSL Modem System level vectoring OSPs

  41. FEXT Cancelled Group 96 Pairs No Alien Disturbers

  42. Vectoring Benefits and Considerations • Vectoring has the potential to cancel crosstalk in a binder: • All users see rates as if they were the onlyuser in the cable • Benefits • 30-50% improvement in speed • Reach 100Mpbs with 2 pair bonding • Considerations • Limited to short loops (less than 3,000ft) • Need system level approach 100 Mbps to > 2500 ft, Using 2 pairs 26 AWG equivalent: Multiply vectored reach by 1.3 for 24 AWG

  43. Downstream Performance Full Cancellation

  44. Upstream Performance Full Cancellation

  45. Conclusions • Complexity of FEXT cancellation will result in longer port training times. • FEXT cancellation for VDSL2 shows great promise for applications in which: • cable size matches the in-domain group size • system level deployment is implemented and group size matches or exceeds the binder size • loops are short • alien crosstalk is minimal. • After FEXT is removed, the resulting low noise floor will likely increase performance sensitivity to impulse noise and component non-linearity

  46. Key Takeaways • System-level approach is best • Best gains (30-50%) with short loops. (<1000ft) • Vectoring is a short loop technology not suitable for CO deployments • ADTRAN knows vectoring. In 2008, ADTRAN received the “Award for Outstanding Contributions to an ATIS Forum or Committee”. This achievement was in recognition for our initiative to provide the industry with a FEXT Channel Model needed for the analysis of FEXT cancellation techniques used in vectoring.

  47. Thank You Please visit: http://adtran.com to learn more. Email info@adtran.com or call 800-9ADTRAN

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