1 DSMDSM

Dynamic Spectrum ManagementDynamic Spectrum Management

John M. CioffiJohn M. CioffiProf. EE, Stanford U.Prof. EE, Stanford U.

Cioffi@stanford.eduCioffi@stanford.edu

And all the work by students:And all the work by students:

Taek Chung, George Ginis, Jeannie Taek Chung, George Ginis, Jeannie Fang, Jungwon Lee, Dimitris Fang, Jungwon Lee, Dimitris

Toumpakaris, & Wei YuToumpakaris, & Wei Yu

July 2002July 2002

2 DSMDSM

Copper has more bw than fiber?Copper has more bw than fiber?

DSL will deliver 100 Mbps symmetric to allDSL will deliver 100 Mbps symmetric to all 50 line bundle (500 meters of cat 3 tp)50 line bundle (500 meters of cat 3 tp)

50 lines (100 Mbps/line) = 5 Gbps 50 lines (100 Mbps/line) = 5 Gbps FTTH shares 622 Mbps among 50 or more homes in FTTH shares 622 Mbps among 50 or more homes in

PON architecture (even “future” systems are 2.5 Gbps)PON architecture (even “future” systems are 2.5 Gbps) So, where is DSL today?So, where is DSL today?

Where is DSL going?Where is DSL going?

fiberfiber

Cable of copper pairCable of copper pair

3 DSMDSM

DSL 200DSL 200XX- (V/M/ADSL)- (V/M/ADSL)

Data , Voice , Video …Data , Voice , Video …

802.11 wireless (802.11,15) orwireless (802.11,15) orother distribution possibleother distribution possiblewithin CPE, 11, 55,within CPE, 11, 55,100-500 Mbps100-500 Mbps

VoDSLInterface

10/100 Mbps10/100 Mbps

A/VDSLA/VDSLCloserCloserDSLAMDSLAMONU/RTONU/RT

FiberFiber(from CO)(from CO)

Enet

1000BT1000BT

routerrouter

Enet.

IEEE 802.X

4 DSMDSM

DSM=Dynamic Spectrum ManagementDSM=Dynamic Spectrum Management

Standard in progress – USA (ANSI / T1E1.4)Standard in progress – USA (ANSI / T1E1.4) Dynamic – loops, xtalk, rates veryDynamic – loops, xtalk, rates very

Not limited by worst-case static situationsNot limited by worst-case static situations Extension to existing Spec ManagementExtension to existing Spec Management

T1.417-2002T1.417-2002 Improve considerably reliability and performanceImprove considerably reliability and performance Cannot have spectrum compatibility at higher speeds without DSMCannot have spectrum compatibility at higher speeds without DSM

Crosstalk effect is too strong for static regulationCrosstalk effect is too strong for static regulation THIS IS A CRUCIAL turning point for DSLTHIS IS A CRUCIAL turning point for DSL

Goals: 100 Mbps symmetric everywhereGoals: 100 Mbps symmetric everywhere & Improve the range of every rate < 100 Mbps& Improve the range of every rate < 100 Mbps

SM (static)SM (static) VDSLVDSL10MDSL10MDSL

ADSL+ADSL+ 100MDSL100MDSL

VDSL-2VDSL-2

DSMDSMHDSL / ADSLHDSL / ADSL

20002000 20012001 20022002 20032003

……

““EFM”EFM”

5 DSMDSM

OutlineOutline

Crosstalk and ManagementCrosstalk and Management Autonomous (de-regulated) DSLAutonomous (de-regulated) DSL Bonded/Vectored DSLBonded/Vectored DSL

6 DSMDSM

DSL’s Challenge: CrosstalkDSL’s Challenge: Crosstalk

Same service provider Same service provider Different service providerDifferent service provider Management?Management?

Spectrum – fixed or staticSpectrum – fixed or static Ok, but performance and reliability severely Ok, but performance and reliability severely

compromisedcompromised

Symmetric versus asymmetricSymmetric versus asymmetric

PhonePhoneCo=BaseCo=Base(DSLAM)(DSLAM)

useruser

useruserNEXTNEXT

FEXTFEXT

7 DSMDSM

Some CrosstalkSome Crosstalk

105

106

107

108

20

25

30

35

40

45

50

55

60

65

Freq (MHz)

cros

stal

k co

uplin

g (d

B)

NEXT - BellcoreNEXT - Bellcore(attenuation)(attenuation)

FEXT Plots

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10000 100000 1000000 10000000

Frequency (Hz)

Lev

el (

dB

) FEXT 1

FEXT 2

FEXT 3

FEXT 4

FEXT – British FEXT – British TelecomTelecom(gain)(gain)

Xtalk noise increases with frequencyXtalk noise increases with frequency

8 DSMDSM

Loop TopologyLoop Topology

Many other configurationsMany other configurations symmetric/asymmetric mixturessymmetric/asymmetric mixtures Data rate mixturesData rate mixtures Shorter linesShorter lines Bonding of linesBonding of lines

CO DSLsCO DSLs

CPECPE DSL DSL

CPECPE DSL DSL

CO DSLCO DSL CPECPE DSL DSL

LT DSLLT DSLCPECPE DSL DSL

9 DSMDSM

ADSL DMT Loading BasicsADSL DMT Loading Basics(adapts to each line)(adapts to each line)

FrequencyFrequency

FrequencyFrequency

AttenAtten

TWISTED-PAIRTWISTED-PAIR

Bits/chanBits/chan

FrequencyFrequency

Bits/chanBits/chan

FrequencyFrequency

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

800 Million phone lines and growing fast!800 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

10 DSMDSM

Evolution of Crosstalk / managementEvolution of Crosstalk / management

timetime

Network

CentralOfficePresent DSL 2002:Present DSL 2002:

autonomousautonomous(no coordination)(no coordination)

SMC for provisioning,SMC for provisioning,Fault isolationFault isolation

1-20 Mbps1-20 Mbps(asymmetric/(asymmetric/symmetric)symmetric)

SMC1

SMC2

CLECDSLAM

ILECDSLAM 1

ILECDSLAM 2

bbiinnddeerr

Network

CentralOfficeContent 1

Content 2 ILEC LTSwitch

router

FiberOr multi-channelDSL

twisted

pair

DSLAM

20-100 Mbps20-100 Mbps(symmetric)(symmetric)

SMC

Evolving DSL 2002+:Evolving DSL 2002+:BondingBonding

VectoringVectoringCommon DSLAMCommon DSLAM

(LT or RT)(LT or RT)

bbiinnddeerr

11 DSMDSM

OutlineOutline Crosstalk and ManagementCrosstalk and Management Autonomous (de-regulated) DSLAutonomous (de-regulated) DSL Bonded/Vectored DSLBonded/Vectored DSL

Network

CentralOfficePresent DSL 2002:Present DSL 2002:

autonomousautonomous(no coordination)(no coordination)

SMC for provisioning,SMC for provisioning,Fault isolationFault isolation

1-20 Mbps1-20 Mbps(asymmetric/(asymmetric/symmetric)symmetric)

SMC1

SMC2

CLECDSLAM

ILECDSLAM 1

ILECDSLAM 2

bbiinnddeerr

12 DSMDSM

Model: Autonomous CaseModel: Autonomous Case

Crosstalk between users is “matrix channel”Crosstalk between users is “matrix channel” ““Interference channel” in information theoryInterference channel” in information theory

Can users be compatible without large loss? (SSM – Can users be compatible without large loss? (SSM – no, DSM - yes)no, DSM - yes)

......

SharedSharedbinderbinderHH(f)(f)

DSL 1DSL 1

DSL KDSL K

DSL 2DSL 2

DSL KDSL K

DSL 1DSL 1

DSL 2DSL 2

13 DSMDSM

DSM Multi-user Rate REGIONSDSM Multi-user Rate REGIONS

Plot of all possible rates of usersPlot of all possible rates of users ADSL & some VDSL use DSM – any point is possibleADSL & some VDSL use DSM – any point is possible

More than 2 users (vector of possible rate-tuples)More than 2 users (vector of possible rate-tuples) Region’s size (volume) can vary with:Region’s size (volume) can vary with:

each bindereach binder transmission methods (i.e., DMT has much larger regions)transmission methods (i.e., DMT has much larger regions)

RRlonglong

RRshortshort

SpectralSpectral pair 1pair 1

Spectral pair 2Spectral pair 2

14 DSMDSM

ANSI DSM ADSL “Blueprint” ExampleANSI DSM ADSL “Blueprint” Example(T1E1.4/2001- 273, 278)(T1E1.4/2001- 273, 278)

ADSLADSLCOCO

ADSLADSLrcvrrcvr

10 + X kft

ADSLADSLRTRT

10 kft

Line 1

Line 25 kft

CO

Same binder FEXT

CLASSIC field problem with ADSL present-day deploymentsCLASSIC field problem with ADSL present-day deployments Long-line often does not work and field personal have to be dispatchedLong-line often does not work and field personal have to be dispatched

Improve the performance of line 1 AUTONOMOUSLY (no coordination) using DSM-mode in ADSL modemsImprove the performance of line 1 AUTONOMOUSLY (no coordination) using DSM-mode in ADSL modems Eliminate problem automaticallyEliminate problem automatically Greatly extend ADSL rangeGreatly extend ADSL range

ADSLADSLrcvrrcvrfiber

15 DSMDSM

InitialInitialShort-line spectra,Short-line spectra,Long-line turns onLong-line turns on

DSM ADSL basic spectrum result

Short-line spectraShort-line spectra

LongLongLineLine

spectraspectra f

Downstream Spectra (2 lines)

Short line yields to long No “DSL hogging”

Enormous improvement on long line At expense of reduced rate on short line

Do so autonomously

IntermediateIntermediateShort-line spectra,Short-line spectra,

IntermediateIntermediateShort-line spectra,Short-line spectra,

16 DSMDSM

Verizon Experimental Loop ConfigurationVerizon Experimental Loop Configuration(T1E1.4/2002-069 – “Bell Atlantic” Test Lab, Maryland)(T1E1.4/2002-069 – “Bell Atlantic” Test Lab, Maryland)

Mainframe

Cable Vault

Remote Side

Mainframe

Cable Vault

CO side Remote Side

Pair 1 of 14 kft, 24

gauge25-pair binder

Pair 16 of 6 kft, 26 gauge

25-pair binder

(Simulates RT portion

of loop)CO side

ATU-C ATU-R

Verizon Broadband Integration LabVerizon Broadband Integration Lab

Simulation of CO-ADSL fed throughRT binder with RT-ADSL

ATU-C ATU-R

Pair 17 of 6 kft, 26 gauge

25-pair binder

(Simulates RT-ADSL

loop)Remote Side

CO ADSLCO ADSL RT ADSLRT ADSL

14 kft14 kft

6 kft6 kft

17 DSMDSM

Crosstalk into pair 17Crosstalk into pair 17

Pair  Noise (dB)        Pair  Noise Pair  Noise (dB)        Pair  Noise (dB)(dB)1     -82.5                   13    -84.41     -82.5                   13    -84.42     -78.1                   14    -80.72     -78.1                   14    -80.73     -74.9                   15    -77.73     -74.9                   15    -77.74     -82.3                 4     -82.3                     16    -63.216    -63.25     -83.0                   18    -67.75     -83.0                   18    -67.76     -84.2                   19    -67.56     -84.2                   19    -67.57     -78.0                   20    -76.97     -78.0                   20    -76.98     -81.0                   21    -80.88     -81.0                   21    -80.89     -75.3                   22    -78.79     -75.3                   22    -78.710    -73.3                   23    -78.010    -73.3                   23    -78.011    -79.6                   24    -73.411    -79.6                   24    -73.412    -82.7                   25    -80.712    -82.7                   25    -80.7

200 300 400 500 600 700 800 900 1000 1100-140

-120

-100

-80

-60

-40

-20

Frequency (kHz)

Co

uplin

g F

unct

ion(

dB

)

Crosstalk Coupling Functions

H12

H21

Used worst-case FEXT coupling pairs for experimentUsed worst-case FEXT coupling pairs for experiment

18 DSMDSM

DSM-ADSL Rate Region (Verizon loops)DSM-ADSL Rate Region (Verizon loops)

Rate-Adaptive produces (9,.1) Rate-Adaptive produces (9,.1) Mode used by Verizon nominally in labMode used by Verizon nominally in lab

Instead, DSM-mode provides (Short, Long) = Instead, DSM-mode provides (Short, Long) = (2, 1.8), (4, 1.4), (6, .9) , and (8, .6) (2, 1.8), (4, 1.4), (6, .9) , and (8, .6)

19 DSMDSM

Telcordia (Bellcore) Results “Blueprint” TestTelcordia (Bellcore) Results “Blueprint” Test(T1E1.4/2002-063)(T1E1.4/2002-063)

ADSLCO

ADSLrcvr

15 kft

ADSLRT

10 kft (fiber) ADSLrcvr

Line 1

Line 2

ADSLRT

10 kft (fiber) ADSLrcvr

5 kft

15 kft

CO

Same binder FEXT

Line 3

Improve the performance of lines 1 and 3 (which is bad under RA Improve the performance of lines 1 and 3 (which is bad under RA operation)operation)

Line 1 only operates at 300 kbps in “normal” modeLine 1 only operates at 300 kbps in “normal” mode

ADSLADSLCOCO

ADSLADSLrcvrrcvr

ADSLADSLRTRT

ADSLADSLrcvrrcvr

ADSLADSLrcvrrcvr

ADSLADSLRTRT

20 DSMDSM

Telcordia DSM-ADSL Rate RegionsTelcordia DSM-ADSL Rate Regionst1e1.4/2002-063t1e1.4/2002-063

lines 1 & 3 (2 held at 1.6 Mbps)lines 1 & 3 (2 held at 1.6 Mbps) lines 1 & 2 (3 removed) – 063R1lines 1 & 2 (3 removed) – 063R1

No coordination (line 2 held at 6 dB margin, 1.6 MbpsNo coordination (line 2 held at 6 dB margin, 1.6 Mbps 4x improvement on Line 1 (was at 300 kbps if line 2 does 4x improvement on Line 1 (was at 300 kbps if line 2 does

RA or margin-max training) – like “Verizon” expt.RA or margin-max training) – like “Verizon” expt. 4x because 15kft, not 20 kft like Verizon4x because 15kft, not 20 kft like Verizon

21 DSMDSM

DSM Algorithm (Iterative-Water-filling)DSM Algorithm (Iterative-Water-filling)

NSR(f)NSR(f)

S(f)S(f)

Water-filling is known optimum on single-user channelWater-filling is known optimum on single-user channel Use DMT, and MINIMIZE POWER for given rate/marginUse DMT, and MINIMIZE POWER for given rate/margin

Best autonomous solution to “interference problem” in binderBest autonomous solution to “interference problem” in binder The more lines that do DSM, the better they all workThe more lines that do DSM, the better they all work

NEVER any worse than existing fixed/static Spectrum ManagementNEVER any worse than existing fixed/static Spectrum Management AUTONOMOUS – no coorination necessary, procedure assures overall best mutual spectra (least AUTONOMOUS – no coorination necessary, procedure assures overall best mutual spectra (least

harmful xtalk) of all DSLS in distributed fashionharmful xtalk) of all DSLS in distributed fashion

22 DSMDSM

3-steps to Broadband DSL3-steps to Broadband DSL

DSMDSM ADSL -Software option in current ADSL modemsADSL -Software option in current ADSL modems ADSL+ & 10M-DSL (DMT only) – iterative wfADSL+ & 10M-DSL (DMT only) – iterative wf 100M-DSL (DMT only) 100M-DSL (DMT only)

ADSL toADSL toD: 7 MbpsD: 7 MbpsU: .3 MbpsU: .3 Mbps1 line1 line0-6 km0-6 km

AMDSL toAMDSL toD: 25 MbpsD: 25 MbpsU: 10 MbpsU: 10 Mbps1-2 lines CO/LT1-2 lines CO/LT0-4 km0-4 km

BDSL toBDSL toD: 100 MbpsD: 100 MbpsU: 100 MbpsU: 100 Mbps1-4 lines/LT1-4 lines/LT0-2 km0-2 km

……20022002 20032003 20042004

Dynamic Spectrum ManagementDynamic Spectrum Management

23 DSMDSM

10MDSL (EFM) Range/Rate Goals [1]10MDSL (EFM) Range/Rate Goals [1]

raterate lineslines Per linePer line LengthLength

(kft)(kft)

GoalGoal

(kft)(kft)

10 M10 M 11 1010 2.52.5 >3.5>3.5

10M10M 22 55 3.53.5 >4.5>4.5

10M10M 33 3.333.33 55 >6>6

10M10M 44 2.52.5 77 >8>8

10M10M 55 22 88 >9>9

4M4M 44 11 1212 >12>12

2M2M 44 .5.5 1515 >15>15

24 DSMDSM

25 10MDSLs in same binder (same length)25 10MDSLs in same binder (same length)

No coordination No coordination 10 Mbps single-line range is 2.5x SSM result (SHDSL)10 Mbps single-line range is 2.5x SSM result (SHDSL) 10 Mbps >1.5 km on 2 lines10 Mbps >1.5 km on 2 lines

VerifiedVerifiedByBy

TelcordiaTelcordia

VerifiedVerifiedByBy

VoyanVoyan

25 DSMDSM

Example PSD for 4000’Example PSD for 4000’

Overlap (EC) to 800 kHzOverlap (EC) to 800 kHz Each has 3 basic bandsEach has 3 basic bands

26 DSMDSM

MDSL with ADSL presentMDSL with ADSL present

Range of ADSL and of MDSL Range of ADSL and of MDSL unaffected if DSM is usedunaffected if DSM is used Not true for Static SM (or SHDSL)Not true for Static SM (or SHDSL)

27 DSMDSM

ADSL at CO, MDSL at RT ADSL at CO, MDSL at RT

Cabinet is 10 kft from CO – last 2 to 6 kft in same binderCabinet is 10 kft from CO – last 2 to 6 kft in same binder ADSL at CO “swamped” by 64 PAMADSL at CO “swamped” by 64 PAM ADSL at CO largely unaffected by IWADSL at CO largely unaffected by IW

M MA A

Fiber, 10 kftFiber, 10 kft Copper, 4 kftCopper, 4 kft

Copper, L kftCopper, L kft12, 14, 1612, 14, 16

28 DSMDSM

VDSL vs MDSL rate regionsVDSL vs MDSL rate regions

Fixed is 998 on V and 1 MHz on MFixed is 998 on V and 1 MHz on M Still exceeds all targets of M and VStill exceeds all targets of M and V

29 DSMDSM

Table Revisted (extra column)Table Revisted (extra column)

Allows mixture of ADSL with MDSL, and VDSL with MDSLAllows mixture of ADSL with MDSL, and VDSL with MDSL Rate regions do reduce in size for VDSLRate regions do reduce in size for VDSL

But all VDSL and MDSL goals still exceededBut all VDSL and MDSL goals still exceeded

Table 2 – Augmentation of Table 1 with IW resultsTable 2 – Augmentation of Table 1 with IW results

Aggregate bit Aggregate bit rate (sym rate (sym payload)payload)

# of # of twisted twisted pairspairs

Average bit rate Average bit rate per pairper pair

Objective Objective loop lengthloop length

Desired Desired loop loop lengthlength

DSM DSM ResultResult

10 Mb/s10 Mb/s 11 10 Mb/s10 Mb/s 2.5 kft2.5 kft >3.5 kft>3.5 kft 5 kft5 kft

10 Mb/s10 Mb/s 22 5 Mb/s5 Mb/s 4 kft4 kft >5 kft>5 kft 8 kft8 kft

10 Mb/s10 Mb/s 33 3.33 Mb/s3.33 Mb/s 5.5 kft5.5 kft >6.5 kft>6.5 kft 9 kft9 kft

10 Mb/s10 Mb/s 44 2.5 Mb/s2.5 Mb/s 7 kft7 kft >8 kft>8 kft 10 kft10 kft

10 Mb/s10 Mb/s 55 2 Mb/s2 Mb/s 8 kft8 kft >9 kft>9 kft achievedachieved

4 Mb/s4 Mb/s 44 1 Mb/s1 Mb/s 12 kft12 kft >12 kft>12 kft achievedachieved

2 Mb/s2 Mb/s 44 512 kb/s512 kb/s 15 kft15 kft >15 kft>15 kft achievedachieved

30 DSMDSM

998 Plan with Iter-water (VDSL)998 Plan with Iter-water (VDSL)

Rates exceed VDSL objectivesRates exceed VDSL objectives Note spectra converges to 998 when 998 is Note spectra converges to 998 when 998 is

present (4000’ MDSL)present (4000’ MDSL)

31 DSMDSM

Basic Principles - SummaryBasic Principles - Summary

No DSL modem should use more No DSL modem should use more transmit power than it needstransmit power than it needs

No DSL modem should use more No DSL modem should use more bandwidth than it needsbandwidth than it needs

Can be solved adaptively and Can be solved adaptively and autonomouslyautonomously Stop proliferating DSL standards and Stop proliferating DSL standards and

incompatible spectrum managementincompatible spectrum management

32 DSMDSM

Basic SolutionBasic Solution

Use/Extend ADSL DMT Frequency GridUse/Extend ADSL DMT Frequency Grid Already on 24 million lines (> 95% of market)Already on 24 million lines (> 95% of market)

ADSL+ = 512 tones down / 128 upADSL+ = 512 tones down / 128 up 10MDSL= 1024 tones down/1024 up10MDSL= 1024 tones down/1024 up VDSL = 2048 up/downVDSL = 2048 up/down 100MDSL 4096 up/down100MDSL 4096 up/down

DSM Spectrum Plan

010002000300040005000

ADSL

ADSL+

10M

DSL

VDSL

100M

DSL

DSL Type

Nu

mb

er o

f to

nes

Down

Up

33 DSMDSM

OutlineOutline

Crosstalk and ManagementCrosstalk and Management Autonomous (de-regulated) DSLAutonomous (de-regulated) DSL Bonded/Vectored DSLBonded/Vectored DSL

Network

CentralOfficeContent 1

Content 2 ILEC LTSwitch

router

FiberOr multi-channelDSL

twisted

pair

DSLAM

timetime

20-100 Mbps20-100 Mbps(symmetric)(symmetric)

SMC

Evolving DSL 2002+:Evolving DSL 2002+:BondingBonding

VectoringVectoringCommon DSLAMCommon DSLAM

(LT or RT)(LT or RT)

bbiinnddeerr

34 DSMDSM

SharedSharedchannelchannel

Coordinated 2-sided Coordinated 2-sided SignalsSignals (vector bonding) (vector bonding)

Full Vectoring ProblemFull Vectoring Problem Highest data ratesHighest data rates

BondedBondedlineslines

ControllerController

BondedBondedlineslines

ControllerController

35 DSMDSM

SharedSharedchannelchannel

DSM Level 2: Coordinated 1-sided DSM Level 2: Coordinated 1-sided SignalsSignals

““broadcastbroadcast” and “” and “multiple-accessmultiple-access” probs in IT” probs in IT One-sided vectoring, FDM of up/downOne-sided vectoring, FDM of up/down

Bonding (vector broadcast and vector MA problems in IT)Bonding (vector broadcast and vector MA problems in IT)

LTLTDSLAMDSLAM

User 1User 1

User 2User 2

User KUser K

......ControllerController

36 DSMDSM

998 with/without Vectoring998 with/without Vectoring

Enormous gain, especially upstream at Enormous gain, especially upstream at shorter lengths where FEXT is largeshorter lengths where FEXT is large

37 DSMDSM

Full Vectoring (sum up/down) Full Vectoring (sum up/down)

100 Mbps range – 500 meters , single line100 Mbps range – 500 meters , single line 1 km on 2 lines1 km on 2 lines >1.5 km on 4 lines>1.5 km on 4 lines

Even when partially vectored, 100 Mbps on 2 lines at 500 m, 1 km on 4 linesEven when partially vectored, 100 Mbps on 2 lines at 500 m, 1 km on 4 lines

38 DSMDSM

Broadband DSLBroadband DSL

Enables video, data, voice services and Enables video, data, voice services and packagingpackaging

Bit rateBit rate # of lines# of lines Rate/lineRate/line RangeRange

100 Mbps100 Mbps 11 100 M100 M 300-500 m300-500 m

100 Mbps100 Mbps 22 50 M50 M 1 – 1.2 km1 – 1.2 km

100 Mbps100 Mbps 44 25 M25 M 1.5-2 km1.5-2 km

39 DSMDSM

3 steps3 steps

ANSI 2001-200R5, 2002-018, 057, 059, 127, 129ANSI 2001-200R5, 2002-018, 057, 059, 127, 129 http://isl.stanford.edu/~cioffi/dsm/index.htmlhttp://isl.stanford.edu/~cioffi/dsm/index.html Looking to collaborate with service/content providers, Looking to collaborate with service/content providers,

equipment/semi companiesequipment/semi companies

ADSL toADSL toD: 7 MbpsD: 7 MbpsU: .3 MbpsU: .3 Mbps1 line1 line0-6 km0-6 km

20022002……

AMDSL toAMDSL toD: 25 MbpsD: 25 MbpsU: 10 MbpsU: 10 Mbps1-2 lines CO/LT1-2 lines CO/LT0-4 km0-4 km

BDSL toBDSL toD: 100 MbpsD: 100 MbpsU: 100 MbpsU: 100 Mbps1-4 lines/LT1-4 lines/LT0-2 km0-2 km

20032003 20042004

Dynamic Spectrum ManagementDynamic Spectrum Management