Broadband Access Over HFC Networks

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Broadband Access over HFC NetworkBroadband Access over HFC Network

Xiaolin LuXiaolin Lu

OFC 1999OFC 1999

AT&T Labs

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What is this?What is this?

An invited speech on Optical Fiber

Communication Conference (1999)

about technology evolution of HFC

Networks

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Toll

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INTERDEPENDENCYINTERDEPENDENCY

Communication

Point-to-point

“On-Demand”

Entertainment

Broadcast

Always there

ServicesServices

BillingBilling

TransportTransport

NetworkNetwork

VOICE VIDEO

Usage-based

Narrowband/

baseband

Point-to-point

Twist pair

Flat rate

RF Broadband

Point-to-multipoint

Coax

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OUTLINEOUTLINE

EVOLUTIN OF CABLE INDUSTRYEVOLUTIN OF CABLE INDUSTRY

MOVING FORWARDMOVING FORWARD

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WHEN IT STARTED … WHEN IT STARTED …

HEHE

Consistent with street layoutConsistent with street layout

Flexible user connectionFlexible user connection

Broadband (1GHz)Broadband (1GHz)

SecuritySecurity

ReliabilityReliability

QualityQuality

Broadcast Tree-and-Branch

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SDV

UpgradeUpgrade -- QualityQuality

-- ReliabilityReliability

-- BandwidthBandwidth

-- UpstreamUpstream

EVOLVINGEVOLVING

TransportTransport

-- LightwaveLightwave

-- RFRF

TerminalTerminal

-- ModemModem

-- ProtocolProtocol

NetworkNetwork

-- DistributionDistribution

-- TrunkTrunk

OperationOperation

-- MonitoringMonitoring

-- ManagementManagement

Broadband

AM-VSB

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EVOLUTION AND REVOLUTIONEVOLUTION AND REVOLUTION

Technology

Need

Linear Lightwave RF & DSP Low-cost lightwave

and WDM

Quality

Reliability

Digital

Services

More

HFC

Cable

Modem

Architecture

Evolution/

Revolution

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Coax to HFCCoax to HFC

HEHE

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Coax to HFCCoax to HFC

HEHE

FN

FN

FN

Increase transport capability

Improve quality and reliability

Challenge for linear lightwave

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CHALLENGES OF AMCHALLENGES OF AM--VSB TRANSMISSIONVSB TRANSMISSION

XTR RCV

Requirements:

CNR 52dB 47dB

CTB/CSO -65dBc -55dBc

Challenges:

- Linearity - Dispersion - Linearity

- Noise - Reflection - Noise

- Chirp - Others

Saleh

Limit

OMDOMD

CIR

CIR

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TREND IN LINEAR LIGHTWAVE/RFTREND IN LINEAR LIGHTWAVE/RF

GaAs RF GaAs RF

Amplifier Amplifier

Digital 2Digital 2--wayway

TrunkTrunk

BroadcastBroadcast

Coax Plant Coax Plant

UpgradeUpgrade

Capacity+

Analog

Digital

Lower cost

Two-way

upgrade

NodeNode

HubHub

NEEDNEED TECHNOLOGYTECHNOLOGY PRODUCT PRODUCT APPLICATIONAPPLICATION

Moderate Moderate

DFB & FP DFB & FP

HighHigh--end end

DFB DFB

ExternalExternal

Modulator Modulator

EDFAEDFA

WDMWDM

HEHE

HubHub

CoaxCoax

AmplifierAmplifier

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60 QPSK channels at 2Mbps/ch

Temperature: 200C ~ 800C

Performance of An Uncooled FP LaserPerformance of An Uncooled FP Laser

Theory

Room Temperature

T>80C

Reflection

log

(BER

)

0.1 2 4 6 8 2 4 6 8

10 2

OMD(%)

-10 -9

-8

-7

-6

-5

-4

-3

-2

1

No TE cooler, no isolator

~ $100

S. Woodward, G. Bodeep, OFC’95

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RF MODEM TECHNOLOGYRF MODEM TECHNOLOGY

Spectral EfficiencyModulation

Technique Theory Practical

CNR

(10-8

)

QPSK 2 1.2 - 2 15

16-QAM 4 2.5 – 3.5 22.5

64-QAM 6 4.5 – 5 28.5

AM-VSB 47

DMUX Carrier

900 S

MUX Carrier

Recovery

900 S

10110 II

QQ QQ

II 10110

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New Transport OpportunitiesNew Transport Opportunities

LowLow--costcost

LightwaveLightwave

Digital SCM System

Broadcast/narrowcast

digital TV

Interactive video

2-way communication

Voice, data, etc

Wireless backhauling

Multimedia Multimedia

DigitizationDigitization

DSPDSP

MPEGMPEG--2, etc2, etc

Digital RF Digital RF

TransmissionTransmission

RF ModemRF Modem

BW efficiencyBW efficiency

RobustnessRobustness

RF/(wireless)RF/(wireless)

FrontFront--endend

Linear LightwaveLinear Lightwave

MaturityMaturity

S

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EVOLUTION AND REVOLUTIONEVOLUTION AND REVOLUTION

Technology

Need

Linear Lightwave RF & DSP Low-cost lightwave

and WDM

Quality

Reliability

Digital

Services

More

HFC

Cable

Modem

Architecture

Evolution/

Revolution

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CHALLENGESCHALLENGES

FN

FN

FN HE

HE

HE

Analog TV

5 50 500 750 1G

Emerging Services

Bandwidth Capacity:Bandwidth Capacity: 55--40MHz/1000s HHP upstream40MHz/1000s HHP upstream

Transport Integrity:Transport Integrity: Ingress noise, dynamic rangeIngress noise, dynamic range

101033--toto--1 Architecture:1 Architecture: CentrallyCentrally--mediated MACmediated MAC

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SOLUTIONSSOLUTIONS

103-to-1

Architecture

Bandwidth

Capacity

Transport

Integrity

UPGRADE

Fiber Node

Segmentation

DWDM Trunk

DOCSIS

High level

modulation

Centrally-

mediated MAC

NetworkNetwork

ModemModem

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Fiber Node SegmentationFiber Node Segmentation

FN

Long cascade coax bus shared by many users (1000s)Long cascade coax bus shared by many users (1000s)

1,200 Homes

HE

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HE

1,200 HHP/FN with 300 HHP/Bus1,200 HHP/FN with 300 HHP/Bus

FN

300 Homes 300 Homes

300 Homes 300 Homes

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XTR

RCV H

L

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H

L

H

L

H

L

H

L

XTR

RCV

Frequency Stacking or DWDM for 4X capacityFrequency Stacking or DWDM for 4X capacity

Closer tracking of ingress noiseCloser tracking of ingress noise

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DISTRIBUTED HEADDISTRIBUTED HEAD--ENDEND

Operation complexityOperation complexity

Cost of CMTS at lower take rateCost of CMTS at lower take rate

Primary

Ring

Primary

Hub

HE

HE FN

FN

HE

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DWDM TRUNKDWDM TRUNK

FN

FN

SH

DWDM transport for endDWDM transport for end--toto--end transparencyend transparency

Route diversity for service protectionRoute diversity for service protection

Consolidate highConsolidate high--end terminals (CMTS)end terminals (CMTS)

Primary

Ring

Primary

Hub

SH

SH

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DWDM TRUNKDWDM TRUNK

1 x

8 D

WD

M

1 x

8 D

WD

M

RCV

RCV

RCV

. . . . . .

l

l

Co

arse

WD

M

RCV

Primary Hub Secondary Hub

Fiber Node

XTR 1.3mm

l

l

l

1 x

8 D

WD

M . . .

1 x

8 D

WD

M

. . . 1.5mm

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Segmentation

4X capacity

SH

SH

MODERN HFC NETWORKMODERN HFC NETWORK

SH Primary

Ring

Primary

Hub

FN

FN

DWDM Transport

End-to-end Transparency

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What If We Succeed?What If We Succeed?

Bandwidth exhaustionBandwidth exhaustion Take rate and multiple linesTake rate and multiple lines

New servicesNew services

User behaviorUser behavior

Transport integrityTransport integrity

1

10

100

1000

10000

10 20 30 40 50 60 70 80 90 100

PerformancePerformance

Del

ay

(m

s)

Users

Life cycle cost Life cycle cost

v.s. v.s.

FrontFront--end costend cost

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ARCHITECTURESARCHITECTURES

FN

Tree-and-Branch

Broadcast

Cascaded

Cell-Based

Narrowcast

Clustered

RN

???

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DWDM

Mini Fiber Node (mFN) Mini Fiber Node (mFN) Mini Fiber Node (mFN) Mini Fiber Node (mFN)

Analog

TV

Digital

TV

5 50 500 750 1G

mFN overlay for a cellmFN overlay for a cell--based digital platformbased digital platform

MultiMulti--purpose infrastructurepurpose infrastructure

5050--100 times more clean two100 times more clean two--way bandwidthway bandwidth

Distributed MAC protocol with better performanceDistributed MAC protocol with better performance

FN

FN

Primary

Ring Primary

Hub

mFN

mFN

mFN

mFN

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Early Version of an mFN PrototypeEarly Version of an mFN Prototype

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Line extender mFN

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Aver

age

del

ay

(m

s)

Number of active users

DELAY COMPARISONDELAY COMPARISON

mFN-NAD Cable modem

0.01

0.1

1

10

100

1000

10 20 30 40 50 60 70 80 90 100

mFN-NAD

CM

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DWDM

Mini Fiber Node (mFN) Mini Fiber Node (mFN) Mini Fiber Node (mFN) Mini Fiber Node (mFN)

Analog

TV

Digital

TV

5 50 500 750 1G

MultiMulti--service platformservice platform

FN

FN

Primary

Ring Primary

Hub

mFN

mFN

mFN

mFN

2G

PCS

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MOVING FORWARDMOVING FORWARD

Linear Linear

LightwaveLightwave

Program Program Data/IPData/IP

CompetitionCompetition

Integrity

More services HE

Coax NetworkCoax Network

HE FN

HFC Upgrade

for two-way

broadband

Software

Hardware

EvolutionEvolution

&&

RevolutionRevolution

Lightwave Lightwave

and RFand RF

RF ModemRF Modem

DSP DSP

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EVOLUTIONEVOLUTION EVOLUTIONEVOLUTION

Demand

Take Rate

Applications

User Behavior

Demand

Take Rate

Applications

User Behavior

Ban

dw

idth

per

Cu

sto

mer

Push Fiber

Deeper

Push Fiber

Deeper

Split Nodes Split Nodes

Higher RF

Efficiency

Higher RF

Efficiency

Time

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Fiber Optics for CableFiber Optics for Cable

102

107

106

105

104

103

86 06 92 00

108

FSA (103 HP/node)

FTTC (102 HP/node)

FTTH

40 ch AM

100 ch AM

Broadcast Two-way Broadband

Fib

er t

erm

inati

on

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White SpaceWhite Space

Volume

$$ Harmonic Lightwaves

Lucent ANTEC

GI

Scientific Atlanta

Ortel

Phillips

C-COR

???

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“There is no wrong technology,“There is no wrong technology,

there are only wrong there are only wrong

assumptions.”assumptions.”