1 DMT: On-Ramp

DMT - based XDSL: The On-DMT - based XDSL: The On-Ramp to the Information Ramp to the Information

SuperhighwaySuperhighway

John M. CioffiJohn M. CioffiStanford UniversityStanford University

CTO & Founder, CTO & Founder, AmatiAmati

July, 1997July, 1997

P:650-723-2150P:650-723-2150F:650-723-8473F:650-723-8473

cioffi@isl.stanford.educioffi@isl.stanford.edu

2 DMT: On-Ramp

New Revenue for Service ProvidersNew Revenue for Service Providers“Superhighway”“Superhighway”

AccessModule

Router

Telco Netw ork

ATM

EntertainmentEntertainment

Broadcast TVVODSportsGames

karokekaroke

ProductivityProductivity

corporate networksconferencing (vide/voic)telecommutingremote access / enterprise

intra-intra-netnet

SpecializedServer

CDROM

Multi-MediaServer

SpecializedServer

CDROM

WWWnewsproducts...

InternetInternet

2-way info2-way info

Info on DemandInfo on Demand

emailfile xfer...

EducationEducation

videolabsaudio...

LARGE CORPORATION

SMALL BUSINESS

HOME

SCHOOLS

CPE

CPE

CPE

CPE

MEDIA

3 DMT: On-Ramp

Twisted Pairs “xDSL”Twisted Pairs “xDSL” Avoid cost of new media deployment (fiber, HFC, Avoid cost of new media deployment (fiber, HFC,

coax, or wireless)coax, or wireless) over 100x increase in bit rates w.r.t. voiceband over 100x increase in bit rates w.r.t. voiceband

modemsmodems Incremental - pay for equipment on only those Incremental - pay for equipment on only those

customers who ask for servicecustomers who ask for service Deploy soonerDeploy sooner

Problem: Problem: HARD TRANSMISSION PROBLEMHARD TRANSMISSION PROBLEM

4 DMT: On-Ramp

Asymmetric DSL (ADSL)Asymmetric DSL (ADSL)

Telco COTelco CO

POTSPOTS(or ISDN)(or ISDN)

SwitchSwitch

splitsplit

split

ATMATMoror

10BT/42210BT/422

8 Mbps

800 kbps ADSLADSL

video switchvideo switch

ADSLADSLAccessAccessMuxMux

(bridge)(bridge)

ADSLADSL

ADSLADSL

.

.

ADSLADSL

internetinternet

5 DMT: On-Ramp

A/xDSL & VDSLA/xDSL & VDSL

..

..

..

to invidualto invidualcustomerscustomers

twisted-pairtwisted-pair

AA/x/xDSLDSL 1-1-66 miles miles

1.5-9 Mbps DS1.5-9 Mbps DS.15/.8 US.15/.8 USto 2 Mbps symto 2 Mbps sym

ANSI T1.413ANSI T1.413

CentralCentralOfficeOffice

PhoneNetwork

ONUNODE

.

.

.

to invidualcustomers

wireless or fiber

twisted-pairVVDSLDSL

.25-1 mile

13-52 Mbps

Symmetric or AsymmetricSymmetric or Asymmetric

neighborhood

6 DMT: On-Ramp

Other “x=“ ‘s Other “x=“ ‘s

Hdsl (symmetric 1.5, 2 Mbps)Hdsl (symmetric 1.5, 2 Mbps) Sdsl (symmetric 384 kbps)Sdsl (symmetric 384 kbps) Idsl (symmetric 160 kbps)Idsl (symmetric 160 kbps) software substitutions with respect to software substitutions with respect to

existing standards - “DSLAM”existing standards - “DSLAM” all rates within existing T1.413 or minor all rates within existing T1.413 or minor

modificationsmodifications

7 DMT: On-Ramp

OutlineOutline

Transmission ChallengesTransmission Challenges DMT vs the transmission challengesDMT vs the transmission challenges ADSL and T1.413 Standard DMTADSL and T1.413 Standard DMT V/XDSL and SDMTV/XDSL and SDMT Implementation TruthImplementation Truth

8 DMT: On-Ramp

Twisted-Pair channelsTwisted-Pair channels

highly variable characteristicshighly variable characteristics attenuation varies withattenuation varies with

lengthlength frequencyfrequency bridge tapsbridge taps gaugegauge

9 DMT: On-Ramp

ADSL LoopsADSL Loops

d d

3-5 mile loops3-5 mile loops loops with bridge tapsloops with bridge taps

10 DMT: On-Ramp

VDSL LoopsVDSL Loops

LOOP VDSL5LOOP VDSL5LOOP VDSL1LOOP VDSL1

11 DMT: On-Ramp

CrosstalkCrosstalk

phone line 1phone line 1

phone line 2phone line 2

NEXTNEXT FEXTFEXT

Dominant noises, increased coupling at higherDominant noises, increased coupling at higherfrequencies - must be mitigated in designfrequencies - must be mitigated in designNEXT - 10NEXT - 10-13-13 f f1.5 1.5 ; FEXT - 10; FEXT - 10-19 -19 d |H(f)|d |H(f)|22 f f22

12 DMT: On-Ramp

Other NoisesOther Noises Radio Noise, AM, HAMRadio Noise, AM, HAM

1 mW differential into rcvr1 mW differential into rcvr must reject HAM by 70-90 dB (VDSL) and must reject HAM by 70-90 dB (VDSL) and

AM by 20-40 dB (ADSL)AM by 20-40 dB (ADSL) Impulse NoiseImpulse Noise

10’s millivolts10’s millivolts 100’s microseconds100’s microseconds narrowband (high amplitude)narrowband (high amplitude) broadband (low amplitude)broadband (low amplitude)

13 DMT: On-Ramp

Radio EmissionsRadio Emissions like crosstalk, except into radio receiverslike crosstalk, except into radio receivers VDSL amateur (HAM) bands Public Safety bandsVDSL amateur (HAM) bands Public Safety bands transmit in discontinuous bandstransmit in discontinuous bands

2 MHz2 MHz 3.5 MHz3.5 MHz

no signalno signalallowedallowed

signalsignalallowedallowed

10 MHz10 MHz

frequency

7 MHz7 MHz-60 dBm/Hz-60 dBm/Hz

-80 dBm/Hz-80 dBm/Hz

14 DMT: On-Ramp

OutlineOutline

Transmission ChallengesTransmission Challenges DMT vs the transmission challengesDMT vs the transmission challenges ADSL and T1.413 Standard DMTADSL and T1.413 Standard DMT V/XDSL and SDMTV/XDSL and SDMT Implementation TruthImplementation Truth

15 DMT: On-Ramp

DMT Loading BasicsDMT Loading Basics(adapts to each line)(adapts to each line)

FrequencyFrequency

FrequencyFrequency

AttenAtten

TWISTED-PAIRTWISTED-PAIR

Bits/chanBits/chan

FrequencyFrequency

Bits/chanBits/chan

FrequencyFrequency

CAPCAP

FrequencyFrequency

AttenAtten

TWISTED-PAIR with TAP, AM/RF, and XTALKTWISTED-PAIR with TAP, AM/RF, and XTALK

AMAM

xtalkxtalk

Bits/chanBits/chan

FrequencyFrequency

Bits/chanBits/chan

600 Million phone lines and growing fast!600 Million phone lines and growing fast!

Bellcore tests, 1993 (ANSI Standard)Bellcore tests, 1993 (ANSI Standard)GTE tests, 1996 ; NSTL, 1996GTE tests, 1996 ; NSTL, 1996

16 DMT: On-Ramp

Competitive Tests , CAP vs DMTCompetitive Tests , CAP vs DMT 1993 - ANSI Bake off - 1.5 Mbps (Bellcore)1993 - ANSI Bake off - 1.5 Mbps (Bellcore)

Again 1996/7 - GTEAgain 1996/7 - GTE 1997 Tests - 6 Mbps/640 kbps1997 Tests - 6 Mbps/640 kbps

CAP RADSL range limit - 1.5 km - coverage 50%CAP RADSL range limit - 1.5 km - coverage 50% DMT range limit - >2.5 km - coverage 95%DMT range limit - >2.5 km - coverage 95% 28 dB improvement28 dB improvement

DMT consumed less power !!DMT consumed less power !!

Loop 4 Loop 6 Loop 9 Loop 18Amati DMT

RTEC QAMATT/WT CAP

+8 +7 >+16 > +10

-6 -8 +7 +1

FAIL FAIL FAIL FAIL

17 DMT: On-Ramp

DMT Impulse ControlDMT Impulse Control

(time)(time)

amplitudeamplitude (AMI,2B1Q, PAM,QAM/CAP, VSB, etc.)

errors with time-domain

errors with time-domain

amplitudeamplitude

(freq)(freq)

no errors with DMT (or other freq-domain methods)no errors with DMT (or other freq-domain methods)

256 Tones is 20-24 dB advantage (before any FEC)

Low latencyLow latency Less memoryLess memory

18 DMT: On-Ramp

1996 Telchoice/NSTLResults1996 Telchoice/NSTLResults

See October 12 issueSee October 12 issue File transfer speeds with TCP/IPFile transfer speeds with TCP/IP Amati DMT modemAmati DMT modem

1.5M/160k ; 4M/384k (also 8M)1.5M/160k ; 4M/384k (also 8M) >99% of bit rate on file transfer>99% of bit rate on file transfer ranges from 15000 ft to 22000 ftranges from 15000 ft to 22000 ft file transfer speed is several times CAP capabilityfile transfer speed is several times CAP capability

CAP modem used 7 Watts (DMT was 6.1W)CAP modem used 7 Watts (DMT was 6.1W)

19 DMT: On-Ramp

Radio EmissionsRadio Emissions like crosstalk, except into radio receivers (BT recording)like crosstalk, except into radio receivers (BT recording)

frequency

VDSLradio receiver

no signalno signalallowedallowed

2 MHz2 MHz 3.5 MHz3.5 MHz 7 MHz7 MHz 10 MHz10 MHz

signalsignalallowedallowed

no VDSLno VDSL CAPCAP DMTDMT CAPCAP DMTDMT CAPCAP

20 DMT: On-Ramp

OutlineOutline

Transmission ChallengesTransmission Challenges DMT vs the transmission challengesDMT vs the transmission challenges ADSL and T1.413 Standard DMTADSL and T1.413 Standard DMT V/XDSL and SDMTV/XDSL and SDMT Implementation TruthImplementation Truth

21 DMT: On-Ramp

Asymmetric DSL (ADSL)Asymmetric DSL (ADSL)

Telco COTelco CO

POTSPOTS(or ISDN)(or ISDN)

SwitchSwitch

splitsplit

split

ATMATMoror

10BT/42210BT/422

8 Mbps

800 kbps ADSLADSL

video switchvideo switch

ADSLADSLAccessAccessMuxMux

(bridge)(bridge)

ADSLADSL

ADSLADSL

.

.

ADSLADSL

internetinternet

22 DMT: On-Ramp

Rate AdaptionRate Adaption

DMT will rate adaptDMT will rate adapt allows connection on almost any line at highest allows connection on almost any line at highest

reliable ratereliable rate match to internet usematch to internet use

0

2

4

6

8

Mbps

Range

0-1.5 miles 1.5-2.5 miles

2.5-3.5 miles 3.5-5 miles

23 DMT: On-Ramp

Design Details - ADSL T1.413 Design Details - ADSL T1.413 (ANSI/ETSI)(ANSI/ETSI)

256 tones - DMT, about 4 kHz (4.375)256 tones - DMT, about 4 kHz (4.375) multiples of 32 kbps, Rate Adaptivemultiples of 32 kbps, Rate Adaptive Full training, OAMP primitivesFull training, OAMP primitives RS FEC, Trellis (4D Wei)RS FEC, Trellis (4D Wei) fast/slow dual latency pathfast/slow dual latency path Issue 2 now virtually complete, adds ATMIssue 2 now virtually complete, adds ATM ITU g.adsl standard evolvingITU g.adsl standard evolving

24 DMT: On-Ramp

DMT Suppliers/Customers - ADSLDMT Suppliers/Customers - ADSL

Suppliers - Alcatel, Amati, Analog Dev, Suppliers - Alcatel, Amati, Analog Dev, Ericsson, Fujitsu, Motorola, NEC, Nokia, Ericsson, Fujitsu, Motorola, NEC, Nokia, Nortel, Siemens, Texas InstrumentsNortel, Siemens, Texas Instruments

Telco’s - DT, FT, BT, Bezec, Swiss PTT, Telco’s - DT, FT, BT, Bezec, Swiss PTT, KT,Telstra, GTE, Pacific Bell, Ameritech, KT,Telstra, GTE, Pacific Bell, Ameritech, SW Bell, Bell South, HKT, Telia, ...SW Bell, Bell South, HKT, Telia, ...

25 DMT: On-Ramp

OutlineOutline

Transmission ChallengesTransmission Challenges DMT vs the transmission challengesDMT vs the transmission challenges ADSL and T1.413 Standard DMTADSL and T1.413 Standard DMT V/XDSL and SDMTV/XDSL and SDMT Implementation TruthImplementation Truth

26 DMT: On-Ramp

Asymmetric VDSLAsymmetric VDSL

Higher Speeds, 2,6,13, 26, 52 Higher Speeds, 2,6,13, 26, 52 MbpsMbps

Shorter Distances .5 to 3 kmShorter Distances .5 to 3 km Symmetric and/or AsymmetricSymmetric and/or Asymmetric STANDARDS PROJECTSTANDARDS PROJECT

ANSI T1E1.4ANSI T1E1.4 ETSI TM6ETSI TM6

6-26 Mbps6-26 Mbps

NODENODE

(i.e., ONU)(i.e., ONU)

fiberfiber

wirelesswireless

1.0 km1.0 km

26 Mbps26 Mbps

Similar to ADSL, exceptSimilar to ADSL, exceptvery low power requirementvery low power requirementshorter distances and higher shorter distances and higher speeds.speeds.

27 DMT: On-Ramp

BLDG 1BLDG 1 BLDG 2BLDG 2

Symmetric VDSLSymmetric VDSL

fiberfiber

wirelesswireless

300 meters/1000 ft.300 meters/1000 ft.

IIMMUUXX

IIMMUUXX

OLDOLD

VDSLVDSLATM: 26 MbpsATM: 26 Mbps

10BT: 10 Mbps10BT: 10 MbpsHDSL: 1.5 MbpsHDSL: 1.5 Mbps

Avoid Inverse Mux costs (large)Avoid Inverse Mux costs (large) connect buildings within campusconnect buildings within campus Symmetric - early market is data com/enterprize netSymmetric - early market is data com/enterprize net progress to full service as telco’s evolveprogress to full service as telco’s evolve

28 DMT: On-Ramp

SDMT “Ping-Pong” SuperframeSDMT “Ping-Pong” Superframe25 25 ss

500 500 ss

DownstreamDownstream““ping”ping”

UpstreamUpstream““pong”pong”

Program length of “ping” and “pong” for Program length of “ping” and “pong” for asymmetric vs symmetricasymmetric vs symmetric

500 microsecond frame/delay, synchronized 500 microsecond frame/delay, synchronized SDMT Group to ANSI/ETSI:SDMT Group to ANSI/ETSI:

Alcatel, Amati, Cadence, NEC, Rockwell, Alcatel, Amati, Cadence, NEC, Rockwell, Samsung, Siemens, SGS-T, TI Samsung, Siemens, SGS-T, TI

Amati/NEC version is 1997 - it’s tiny! Amati/NEC version is 1997 - it’s tiny! “Piccolo”“Piccolo”

DownstreamDownstream““ping”ping”

UpUp““pong”pong”

29 DMT: On-Ramp

Asymmetric Range/RateAsymmetric Range/Rate

30 DMT: On-Ramp

Symmetric Range/RateSymmetric Range/Rate

31 DMT: On-Ramp

OutlineOutline

Transmission ChallengesTransmission Challenges DMT vs the transmission challengesDMT vs the transmission challenges ADSL and T1.413 Standard DMTADSL and T1.413 Standard DMT V/XDSL and SDMTV/XDSL and SDMT Implementation TruthImplementation Truth

32 DMT: On-Ramp

•Two VLSI approaches to “x”DSLTwo VLSI approaches to “x”DSL

Telecom semiconductor approachTelecom semiconductor approach (Motorola, Alcatel, SGS-T, ADI, NEC)(Motorola, Alcatel, SGS-T, ADI, NEC) single chip integrated analog/digitalsingle chip integrated analog/digital ATM interfaces - full serviceATM interfaces - full service

Datacom semiconductor approachDatacom semiconductor approach (Rockwell, TI, Amati, Mo-IS)(Rockwell, TI, Amati, Mo-IS) Heavy softwareHeavy software CO concentrates, modem changes through CO concentrates, modem changes through

softwaresoftware

33 DMT: On-Ramp

Power/Price of Concentrated Power/Price of Concentrated solutionsolution

< ADSL< ADSL power under 1 W/line at COpower under 1 W/line at CO Price - the power supply dominates at Price - the power supply dominates at

CO sideCO side RT is usual modem priceRT is usual modem price

34 DMT: On-Ramp

ConclusionConclusion

TP transmission hardTP transmission hard DMT excellent matchDMT excellent match

good performancegood performance lowest power/costlowest power/cost truly availabletruly available Widely deployed and in many Telco’s Widely deployed and in many Telco’s

network plansnetwork plans