1. ® Adtran, Inc. 2011 All rights reserved

2. 2 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential Vectoring De-mystified Market Drivers Understanding Vectoring Vectoring Described Benefits of System-Level Implementation

3. 3 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential National Goals by 2020: Ubiquitous 100Mbps Broadband Reaching 2020 Goal is of National and Global Importance US: 100Mbps to 100 Million households France: 100Mbps to 70% of subscribers Australia: 100 Mbps to 90% households Germany: 100Mbps to 50% of subscribers

4. 4 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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

5. 5 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential And Drives Business Success Launched in the last 6 years Super connected subscribers will lead to new industries and companies we can’t even imagine yet Higher bandwidth results in more exciting applications which leads to increased adoption and higher revenue per user

6. 6 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 100Mbps+ Downstream: 25x faster than today’s average 4Mbyte photo in 1/3 second A complete album in 5 sec An Entire HD movie in less than 10 min Multi-angle 3D HDTV Cloud based Multi- screen 3D Gaming.

7. 7 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 100Mbps: A Key Service Offering 100Mbps services will be mainstream by 2015

8. 8 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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 100Mbps: A Key Service Offering

9. 9 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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…

10. 10 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential Vectoring De-mystified Market Drivers Understanding Vectoring Vectoring Described Benefits of System-Level Implementation

11. 11 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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)

12. 12 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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). Two bits Three bits Four bits

13. 13 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential What Is Crosstalk? DSL2 DSL1 DSL2 FEXT Coupling DSL2 DSL1 DSL2 NEXT Coupling

14. 14 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential ANSI Crosstalk Noise Models

15. 15 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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

16. 16 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential ADSL2+ 11 Bit Constellation

17. 17 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential What is Vectoring? +FEXT -FEXT +FEXT

18. 18 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential G.Vector ITU Recommendation G.993.5

19. 19 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential Why Vector Profile 17 Instead of Using Profile 30?

20. 20 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential Why Vector Profile 17 Instead of Profile 30?

21. 21 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential Vectoring De-mystified Market Drivers Understanding Vectoring Vectoring Described Benefits of System-Level Implementation

22. 22 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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

23. 23 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential Aligned Synch Symbols Enable Training Down Synch 1 DMT 2 DMT 3 DMT 4 time Down Synch 1 DMT 2 DMT 3 DMT 4 time Down Synch 1 DMT 2 DMT 3 DMT 4 time DMT 1 DMT 2 DMT 3 Up Synch 4 time DMT 1 DMT 2 DMT 3 Up Synch 4 time DMT 1 DMT 2 DMT 3 Up Synch 4 time Downstream Ports Upstream Ports Down Synch 1 time Up Synch 4 time New Port

24. 24 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential Estimating the Crosstalk. The CPE reports the slicer error measured on the synch symbols and sends it back to the DSLAM

25. 25 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential DSL Transceivers EncoderFramer EncoderFramer EncoderFramer EncoderFramer Modulator DSL Transceiver

26. 26 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential G.993.5: G.vector EncoderFramerModulator EncoderFramerModulator EncoderFramerModulator EncoderFramerModulator Vector Control Entity Precoder

27. 27 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential G.993.5: G.vector EncoderFramerModulator EncoderFramerModulator EncoderFramerModulator EncoderFramerModulator Vector Control Entity Precoder EncoderFramer Modulator EncoderFramer Modulator EncoderFramer Modulator EncoderFramer Modulator Vector Control Entity Precoder DSL Modem

28. 28 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential G.vector: Vector Control Entity (VCE) FramerModulator FramerModulator FramerModulator FramerModulator Vector Control Entity Precoder DSL Modem Vector Control Entity (VCE): coordinates initialization of DSL links: orderly join/leave process Encoder

29. 29 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential G.Vector Steady State Operation 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 EncoderFramerModulatorPrecoder EncoderFramerModulatorPrecoder EncoderFramerModulatorPrecoder Data SyncData SyncData SyncData Encoder DSL Modem

30. 30 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential G.vector: Adding a Line 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 EncoderFramerModulatorPrecoder EncoderFramerModulatorPrecoder EncoderFramerModulatorPrecoder EncoderFramerModulatorPrecoder Data SyncData SyncData SyncData SyncData Encoder DSL Modem Joining Modem DSL Modem

31. 31 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential Board Level FEXT Cancellation (across DSPs and VCE) DSP 1 DSP 2 DSP 3 DSP 4 Cable Plant

32. 32 ADTRAN 2010 All rights reserved Background on Binders Binder 1 Binder 2Binder 3 New line cards or additional systems added No 1 to 1 correlation between systems and binders

33. 33 ADTRAN 2010 All rights reserved The Problem with Vectoring Some Pairs Cannot be part of the Team Crosstalk (FEXT) Pairs in the same binder need to be handled as a single group to effectively implement vectoring

34. 34 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential Deployment Strategy – FEXT Cancellation = Binder Management

35. 35 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential Measured Results: Downstream 12 13 Binder Vectoring: 24 (Left) Vectored + 24 (Right) unvectored Cable Vectoring: 48 lines (24L (rates shown) + 24R) in one vector group

36. 36 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential Measured Results: Upstream 12 13 Binder Vectoring: 24 (Left) Vectored + 24 (Right) unvectored Cable Vectoring: 48 lines (24L (rates shown) + 24R) in one vector group

37. 37 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential Vectoring De-mystified Market Drivers Understanding Vectoring Crosstalk, Bonding and Binder Management Vectoring Described Benefits of System- Level Implementation

38. 38 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential System Level FEXT Cancellation DSP 1 DSP 2 DSP 3 DSP 4 Cable Plant DSP 1 DSP 2 DSP 3 DSP 4 Cable Plant DSP 1 DSP 2 DSP 3 DSP 4 Cable Plant

39. 39 ADTRAN 2010 All rights reserved The Solution is a System Approach Letting Everyone Join the Team Crosstalk (FEXT) 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

40. 40 ADTRAN 2010 All rights reserved Board Level to System Level Upgradeability DSL Modem Binder Card 1 DSL Modem Card 2 Resource Card 3 Card 4 4 Cards = 192 Ports 3 Cards = 144 Ports 2 Cards = 96 Ports 1 Cards = 48 Ports

41. 41 ADTRAN 2010 All rights reserved OSP Board Level to System Level Upgradeability DSL Modem Binder DSL Modem System level vectoring OSPs DSL Modem Initially Single OSP has internal BLV

42. 42 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential FEXT Cancelled Group 96 Pairs No Alien Disturbers

43. 43 ADTRAN 2010 All rights reserved Vectoring Benefits and Considerations Vectoring has the potential to cancel crosstalk in a binder: All users see rates as if they were the only user 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 26 AWG equivalent: Multiply vectored reach by 1.3 for 24 AWG 100 Mbps to > 2500 ft, Using 2 pairs

44. 44 ADTRAN 2010 All rights reserved Downstream Performance Full Cancellation

45. 45 ADTRAN 2010 All rights reserved Upstream Performance Full Cancellation

46. 46 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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

47. 47 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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.

48. ® Adtran, Inc. 2011 All rights reserved Thank You Please visit: http://adtran.com to learn more.http://adtran.com Email info@adtran.com or call 800-9ADTRANinfo@adtran.com