Adtran Inc 2011 All rights reserved Vectoring Demystified

® Adtran, Inc. 2011 All rights reserved

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

National Goals by 2020: Ubiquitous 100 Mbps Broadband US: 100 Mbps to 100 Million households France: 100 Mbps to 70% of subscribers Germany: 100 Mbps to 50% of subscribers Reaching 2020 Goal is of National and Global Importance Australia: 100 Mbps to 90% households ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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 ® Adtran, Inc. 2011 A rights reserved Super connected subscribers will lead to new industries and companies we can’t even imagine yet Proprietary and Confidential 5

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

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

100 Mbps: A Key Service Offering • Numerous national and regional broadband plans give 100 Mbps as a targeted speed • Cable operators are able to offer a 100 Mbps tier with DOCSIS 3. 0 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 8

Can Wireline Service Providers Compete? • FTTH is the ultimate goal but still costprohibitive in many deployment scenarios • Telcos can be competitive with copper – 100 Mbps is practical and economical with VDSL 2 vectoring and bonding • Let’s see how… ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 9

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

VDSL 2 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 VDSL 2 (G. 993. 2 ) Has Tone Spacing of 4. 3125 k. Hz – 8. 625 k. Hz for Profile 30 a. The Upstream Spectrum is Separated From Downstream. This Type of Segregation is Frequency Division Duplexing (FDD) ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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-tonoise ratio (SNR). Three bits Two bits Four bits ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 12

What Is Crosstalk? NEXT Coupling DSL 1 DSL 2 FEXT Coupling DSL 1 DSL 2 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 13

ANSI Crosstalk Noise Models ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 15

ADSL 2+ 11 Bit Constellation ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 16

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

G. Vector ITU Recommendation G. 993. 5 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 18

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

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

Vectoring De-mystified • Market Drivers • Understanding Vectoring • Vectoring Described • Benefits of System-Level Implementation ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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 ® Adtran, Inc. 2011 A rights reserved New Line Error Feedback Proprietary and Confidential 22

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

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

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

G. 993. 5: G. vector Framer Encoder Precoder Modulator Vector Control Entity ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 26

G. 993. 5: G. vector Framer Encoder Framer Modulator Encoder Precoder Modulator Framer Precoder Framer Modulator DSL Modem Encoder Precoder Modulator Vector Control Entity ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 27

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

G. Vector Steady State Operation Framer Encoder Precoder Modulator Data Data Sync Data Data DSL Modem Framer Encoder Precoder Modulator Data Sync Data DSL Modem 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 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 29

G. vector: Adding a Line Framer Encoder Precoder Modulator Data Data Sync Data Data DSL Modem Framer Encoder Precoder Modulator Data Data Sync Data Data Joining DSL Modem 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 learns crosstalk couplings from joining modem, updates coefficients for precoders Joining modem can now send data ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 30

Board Level FEXT Cancellation (across DSPs and VCE) DSP 2 DSP 3 DSP 4 Cable Plant DSP 1 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 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 ADTRAN 2010 All rights reserved 32

The Problem with Vectoring Some 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) ADTRAN 2010 All rights reserved 33

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

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

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

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

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

The Solution is a System Approach Letting 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) ADTRAN 2010 All rights reserved 39

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

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

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

Vectoring Benefits and Considerations Benefits – 30 -50% improvement in speed – Reach 100 Mpbs with 2 pair bonding 10 Us 0 M ing bp 2 s to pa irs > 25 00 • All users see rates as if they were the only user in the cable ft, • Vectoring has the potential to cancel crosstalk in a binder: Considerations – Limited to short loops (less than 3, 000 ft) – Need system level approach ADTRAN 2010 All rights reserved 26 AWG equivalent: Multiply vectored reach by 1. 3 for 24 AWG 43

Downstream Performance Full Cancellation ADTRAN 2010 All rights reserved 44

Upstream Performance Full Cancellation ADTRAN 2010 All rights reserved 45

Conclusions • Complexity of FEXT cancellation will result in longer port training times. • FEXT cancellation for VDSL 2 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 ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 46

Key Takeaways • System-level approach is best • Best gains (30 -50%) with short loops. (<1000 ft) • Vectoring is a short loop technology not suitable for CO deployments 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. • ADTRAN knows vectoring. ® Adtran, Inc. 2011 A rights reserved Proprietary and Confidential 47

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