Invited speech on Optical Fiber Communication Conference, 1999

1. Broadband Access over HFC Network
Xiaolin Lu
OFC 1999
AT&T Labs
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2. What is this?
 Aninvited speech on Optical Fiber
Communication Conference (1999)
about technology evolution of HFC
Networks
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3. Toll
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4. INTERDEPENDENCY
VOICE VIDEO
 Communication  Entertainment
Services  Point-to-point  Broadcast
 “On-Demand”  Always there
Billing  Usage-based  Flat rate
 Narrowband/  RF Broadband
Transport
baseband
 Point-to-point  Point-to-multipoint
Network  Coax
 Twist pair
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5. OUTLINE
 EVOLUTIN OF CABLE INDUSTRY
 MOVING FORWARD
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6. WHEN IT STARTED …
HE
 Broadcast Tree-and-Branch
 Consistent with street layout  Security
 Flexible user connection  Reliability
 Broadband (1GHz)  Quality
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7. EVOLVING
Transport
- Lightwave
- RF
Network
 Upgrade - Distribution
- Quality - Trunk
 Broadband
SDV  AM-VSB
- Reliability
- Bandwidth Terminal
- Upstream
- Modem
- Protocol
Operation
- Monitoring
- Management
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8. EVOLUTION AND REVOLUTION
Need
Architecture
More Evolution/
Revolution
Digital Cable
Services
Modem
Quality
Reliability
HFC
Linear Lightwave RF & DSP Low-cost lightwave Technology
and WDM
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9. Coax to HFC
HE
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10. Coax to HFC
FN
FN
HE
FN
 Increase transport capability
 Improve quality and reliability
 Challenge for linear lightwave
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11. CHALLENGES OF AM-VSB TRANSMISSION
AM-
XTR RCV
Requirements:
CNR 52dB 47dB
CTB/CSO -65dBc -55dBc
Saleh
Limit
Challenges:
CIR
- Linearity - Dispersion - Linearity
- Noise - Reflection - Noise
- Chirp - Others
OMD
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12. TREND IN LINEAR LIGHTWAVE/RF
NEED TECHNOLOGY PRODUCT APPLICATION
Moderate  Node
Digital 2-way
2-
DFB & FP  Hub
High-
High-end
DFB
 Capacity+
 Analog
 Digital External  HE  Trunk
 Lower cost Modulator  Hub  Broadcast
 Two-way
upgrade
 EDFA
 WDM
GaAs RF Coax Coax Plant
Amplifier Amplifier Upgrade
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13. Performance of An Uncooled FP Laser
 No TE cooler, no isolator  60 QPSK channels at 2Mbps/ch
 ~ $100  Temperature: 200C ~ 800C
-2
Theory
Room Temperature
-3 T>80C
Reflection
log(BER)
-4
-5
-6
-7
-8
-9
-10
2 4 6 8 2 4 6 8 2
0.1 1 10
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14. RF MODEM TECHNOLOGY
I I
10110 10110
DMUX Carrier Carrier MUX
S S Recovery
900 900
Q Q
Modulation Spectral Efficiency CNR
Technique Theory Practical (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
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15. New Transport Opportunities
DSP Multimedia
 MPEG-2,
MPEG- etc Digitization
RF Modem Digital SCM System
 BW efficiency
 Robustness  Broadcast/narrowcast
digital TV
Digital RF
Transmission S  Interactive video
RF/(wireless)  2-way communication
 Front-end
Front-  Voice, data, etc
 Wireless backhauling
Linear Lightwave Low-
Low-cost
 Maturity Lightwave
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16. EVOLUTION AND REVOLUTION
Need
Architecture
More Evolution/
Revolution
Digital Cable
Services
Modem
Quality
Reliability
HFC
Linear Lightwave RF & DSP Low-cost lightwave Technology
and WDM
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17. CHALLENGES
HE FN
HE FN
HE
FN
Analog Emerging
TV Services
5 50 500 750 1G
 Bandwidth Capacity: 5-40MHz/1000s HHP upstream
 Transport Integrity: Ingress noise, dynamic range
 103-to-1 Architecture:
to- Centrally-
Centrally-mediated MAC
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18. SOLUTIONS
Bandwidth UPGRADE
Capacity  Fiber Node
Network
Segmentation
 DWDM Trunk
Transport
Integrity DOCSIS
 High level
modulation Modem
 Centrally-
103-to-1 mediated MAC
Architecture
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19. Fiber Node Segmentation
HE FN
1,200 Homes
 Long cascade coax bus shared by many users (1000s)
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20. Fiber Node Segmentation
300 Homes 300 Homes
HE FN
300 Homes 300 Homes
 1,200 HHP/FN with 300 HHP/Bus
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21. Fiber Node Segmentation
RCV H
XTR L
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22. Fiber Node Segmentation
H H
L L
RCV
XTR
H H
L L
 Frequency Stacking or DWDM for 4X capacity
 Closer tracking of ingress noise
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23. DISTRIBUTED HEAD-END
HEAD-
HE
FN
Primary Primary
Hub
HE
Ring
FN
HE
 Operation complexity
 Cost of CMTS at lower take rate
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24. DWDM TRUNK
SH
FN
Primary Primary
Hub
SH
Ring
FN
SH
 DWDM transport for end-to-end transparency
end-to-
 Route diversity for service protection
 Consolidate high-end terminals (CMTS)
high-
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25. DWDM TRUNK
Primary Hub Secondary Hub
1.3mm
XTR
Coarse
WDM
l
1 x 8 DWDM
1 x 8 DWDM
l
l
. .
.
.
. . Fiber Node
1.5mm RCV
RCV l
1 x 8 DWDM
1 x 8 DWDM
RCV l
RCV
.
. .
.
. .
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26. MODERN HFC NETWORK
SH FN
Primary Primary
Hub
SH
Ring
SH FN
DWDM Transport Segmentation
End-to-end Transparency 4X capacity
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27. What If We Succeed?
 Bandwidth exhaustion  Transport integrity
 Take rate and multiple lines
 New services
 User behavior
 Performance
10000
1000
Delay (ms)
100
Life cycle cost
10
v.s.
1
10 20 30 40 50 60 70 80 90 100 Front-
Front-end cost
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Users

28. ARCHITECTURES
Tree-and-Branch
 Broadcast FN
 Cascaded
???
Cell-Based
 Narrowcast RN
 Clustered
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29. Mini Fiber Node (mFN)
mFN
FN mFN
Primary Primary
Ring Hub
mFN
FN mFN
DWDM
Analog Digital
TV TV
5 50 500 750 1G
 mFN overlay for a cell-based digital platform
cell-
 Multi-
Multi-purpose infrastructure
 50-
50-100 times more clean two-way bandwidth
two-
 Distributed MAC protocol with better performance
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30. Early Version of an mFN Prototype
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31. Line extender mFN
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32. DELAY COMPARISON
1000
100
Average delay (ms)
10 mFN-NAD
CM
1
0.1
mFN-NAD Cable modem
0.01
10 20 30 40 50 60 70 80 90 100
Number of active users
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33. Mini Fiber Node (mFN)
mFN
FN mFN
Primary Primary
Ring Hub
mFN
FN mFN
DWDM
PCS
Analog Digital
TV TV
5 50 500 750 1G 2G
 Multi-
Multi-service platform
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34. MOVING FORWARD
Software
 Data/IP
Program  Competition
Coax Network HFC Upgrade Evolution
 Integrity
 More services for two-way &
HE HE FN
broadband Revolution
 Lightwave
Linear
and RF
Lightwave
 RF Modem
Hardware  DSP
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35. EVOLUTION
Demand
Bandwidth per Customer
Take Rate
Applications
User Behavior
Push Fiber
Deeper
Split Nodes
Higher RF
Efficiency
Time
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36. Fiber Optics for Cable
108 FTTH
107
FTTC (102 HP/node)
106
Fiber termination
105 FSA (103 HP/node)
100 ch AM
104
103
102
40 ch AM
86 92 00 06
Broadcast Two-way Broadband
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37. White Space
$$
Harmonic Lightwaves
Phillips GI
Scientific Atlanta
ANTEC Ortel
Lucent
C-COR
???
Volume
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38. “There is no wrong technology,
there are only wrong
assumptions.”
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