ACCESS TECHNOLOGY  innovations in AT&T Labs           Xiaolin Lu         March, 1999 @ Caltech         AT&T Labs
AT&T Labs - RESEARCH                              Larry Rabiner                              Vice President               ...
Lightwave Technology in AT&T Labs       Long-Haul                    AccessWDM/xDFA          Optical                      ...
ACCESS ?Toll
INTERDEPENDENCY                   VOICE                VIDEO             Communication          EntertainmentServices   ...
ACCESS ENVIRONMENT LEC                                                    Cable                   Voice                Vid...
A HISTORICAL PERSPECTIVE        LEC-        LEC-Centric  - Twist Pair  - Circuit switch  - Voice & low speed data         ...
CHANGING PERSPECTIVESTelco-Centric                                     Mosaic                       RF and DSP            ...
Ten Year Performance Improvement WAN Bandwidth 2                                            2000 Processor Power 2        ...
NETWORK TRAFFIC                 1000                            Voice                 800                            DataT...
ACCESS REVOLUTION   Interconnect routers with high-speed    Regional / Metro    (OC3  OC48  …) ports                   ...
END-TO- END-TO-END NETWORKING                                                 National                                    ...
Optical Regional Access Hierarchical Network                                         Backbone Network                    F...
COMPETING WIRED ACCESS SYSTEMSFIBER-TO-THE-FIBER-TO-THE-CURB (FTTC)                                ONU           Switched...
ACCESS OPTIONS               STRATEGY   MENTALITY   PREFERRED SYSTEMS                          Operation                  ...
EVOLVING                                    Transport                                     - Lightwave                     ...
EVOLUTION AND REVOLUTION Need                                            Architecture  More                               ...
Coax to HFCHE
Coax to HFC                               FN     FNHE                              FN         Increase transport capabili...
CHALLENGES OF AM-VSB TRANSMISSION               AM- XTR                         RCVRequirements:CNR              52dB     ...
RF MODEM TECHNOLOGY        I                                                               I10110                         ...
Performance of An Uncooled FP Laser   No TE cooler, no isolator                              60 QPSK channels at 2Mbps/c...
New Transport Opportunities       DSP         Multimedia MPEG-2,  MPEG-      etc   Digitization RF Modem                 ...
EVOLUTION AND REVOLUTION Need                                            Architecture  More                               ...
CHALLENGES          HE                  FN                    HE                  FN    HE                                ...
SOLUTIONSBandwidth             UPGRADE Capacity           Fiber Node                                    Network          ...
Fiber Node SegmentationHE                      FN                                 1,200 Homes   Long cascade coax bus sha...
Fiber Node Segmentation         300 Homes                300 HomesHE                      FN            300 Homes        3...
DISTRIBUTED HEAD-END                      HEAD-                        HE                                           FNPrim...
DWDM TRUNK                      SH                                       FNPrimary   Primary            Hub               ...
DWDM TRUNKPrimary Hub                               Secondary Hub                                  1.3mmXTR               ...
MODERN HFC NETWORK                         SH                   FNPrimary   Primary            Hub                        ...
What If We Succeed?               Bandwidth exhaustion                                    Transport   integrity         ...
ARCHITECTURESTree-and-Branch   Broadcast       FN   Cascaded                                 ???Cell-Based   Narrowcast...
Mini Fiber Node (mFN)                                                                     mFN                             ...
Early Version of an mFN Prototype
Line extender   mFN
DELAY COMPARISON                     1000                     100Average delay (ms)                      10               ...
Mini Fiber Node (mFN)                                                               mFN                                   ...
EVOLUTION                         DemandBandwidth per Customer                         Take Rate                         ...
Fiber Optics for Cable                    108        FTTH                    107                               FTTC (102 H...
PASSIVE OPTICAL NETWORKSCONVENTIONAL TDM PON                                               3       2   1         1   LASER...
WIRELESS ACCESS SYSTEMS                                        Cellular                                - Narrowband/Mobili...
Broadband Wireless Field Experiment                                                            Modem    Internet         B...
Wireless Propagation Data
Wireless: Tricks to Increase Capacity & Peak Rate              What                                  How Advanced Coding  ...
SUMMARY   Emerging technologies, new service opportunities and    competition are driving wide variety of access    infra...
“There is no wrong technology,    there are only wrong         assumptions.”
Access Technology - innovations in AT&T Labs
Access Technology - innovations in AT&T Labs
Access Technology - innovations in AT&T Labs
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Access Technology - innovations in AT&T Labs

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Seminar to Caltech professors and graduate students about innovations in AT&T Labs; March, 1999

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Access Technology - innovations in AT&T Labs

  1. 1. ACCESS TECHNOLOGY innovations in AT&T Labs Xiaolin Lu March, 1999 @ Caltech AT&T Labs
  2. 2. AT&T Labs - RESEARCH Larry Rabiner Vice President Laboratories Information Communications Information Speech & Image Network Services Networking and Systems & Services Infrastructure Sciences Processing Research Distributed Systems Research Research Research Services Research Chief Scientist Ron Brachman Ted Darcie Rob Calderbank David Berkley Dave Belanger Hamid Ahmadi Specification & Algorithm Artificial Intelligence Wireless Systems Mathematics and Speech Processing Innovative Services Research Principles Nelson Sollenberger Cryptography Software & Technology David Unger Michael Merritt Michael Kearns Andrew Odlyzko Broadband Wireless Bishnu Atal Information Systems Network Mathematics Machine Learning and Systems Communications & Analysis Research Sandy Fraser Information Retrieval Paul Henry N. Seshadri Rich Cox Ken Church Albert Greenberg Fernando Pereira Wireless Statistics Candace Kamm Software Systems Systems & Networking Human / Computer Communications Daryl Pregibon Phong Vo Resources Chief Interface Larry Greenstein Jay Wilpon Frank Pirz Scientist Emeritus Julia Hirschberg Algorithms and Large-Scale Broadband Access Optimization Image Processing Programming Networking Research Secure Systems Adel Saleh David Johnson Software & Technology Bjarne Stroustrup Charles Kalmanek David Maher Lightwave Networks Algorithms and Barry Haskell Information Services Distributed Systems Online Platforms Bob Tkach Distributed Data John Denker Michael Merritt (Acting) Gregg Vesonder Joan Feigenbaum Yann LeCun Communications Customer Information Database Research Adaptive Information Technology Behzad Shahraray Mike Wish H. V. (Jag) Jagadish Services Robert R. Miller Larry Jackel Information Consumer Electronics Ron Graham Visualization Ed Chen Stephen North Broadband Services Norm SchryerUnofficial 10/1/98
  3. 3. Lightwave Technology in AT&T Labs Long-Haul AccessWDM/xDFA Optical ORAN PON HFCHigh Capacity Networking
  4. 4. ACCESS ?Toll
  5. 5. INTERDEPENDENCY VOICE VIDEO  Communication  EntertainmentServices  Point-to-point  Broadcast  “On-Demand”  Always there Billing  Usage-based  Flat rate  Narrowband/  RF BroadbandTransport baseband  Point-to-point  Point-to-multipointNetwork  Coax  Twist pair
  6. 6. ACCESS ENVIRONMENT LEC Cable Voice Video  Narrowband  Broadband  Circuit Switch  Broadcast  Dedicated  Shared  Synchronous  Always there  Usage-based  Flat-rate billing billing DBS/LMDSCellular /MMDS
  7. 7. A HISTORICAL PERSPECTIVE LEC- LEC-Centric - Twist Pair - Circuit switch - Voice & low speed data  Regulated - Monopoly  DLC - Access charge  ISDN  Voice-oriented Voice- Point-to- Point-to-point Fiber-To-The- Fiber-To-The-Home
  8. 8. CHANGING PERSPECTIVESTelco-Centric Mosaic RF and DSP  Wired/wireless  Modem technology  Wired  Compression/codec  Broadcast  Switched /narrowcast  Broadband SCM Lightwave  Broadband /narrowband  Video + voice + data  Reliable + low-cost  Synchronous Data Applications  Asynchronous  Internet  Piggy-back  Monopoly Legislation  Competition  Time-to-market Time-to-  Telecom Reform  Techno-economic Techno-
  9. 9. Ten Year Performance Improvement WAN Bandwidth 2 2000 Processor Power 2 1000 Router Engine Performance/Price 1 1000 Internet Traffic 2 1000 Bandwidth to Homes 3 13Sources: 1. Business Communications Reviews, Sept. 1997 2. AT&T 3. Dataquest
  10. 10. NETWORK TRAFFIC 1000 Voice 800 DataTraffic (Gb/s) 600 Total 400 200 0 1990 1995 2000 2005 2010 K.G. Coffman and A. Odlyzko AT&T Labs
  11. 11. ACCESS REVOLUTION Interconnect routers with high-speed Regional / Metro (OC3  OC48  …) ports Networking Migration of corporate LAN bandwidth Broadband to consumers (1  10  100 Mb/s) Wireline Access Intense competition between broadband Broadband Fixed Wireless Access access providers Strong demand for mobile/tetherless 3rd-Generation Mobile Wireless voice and emerging data capabilities
  12. 12. END-TO- END-TO-END NETWORKING National Metropolitan/Regional LocalWireless Cable Copper Pair Fiber Other Access
  13. 13. Optical Regional Access Hierarchical Network Backbone Network Feeder Ring Multi-fiber WDM Ring POP Configurable Nodes Directly Connected Customer Distribution Network Egress Passive, WDM Node Rings, Trees, Buses Access Single-Wavelength Ring Node Electronic TDM Feeder Ring Passive Access AccessDistribution Node Node ADM Tree Single- ADM Directly Wavelength ADM Connected Ring Single- ADM Passive ADM Wavelength Distribution ADM Ring Ring ADM - Customer Premises - Passive Splitter or Add/Drop ADM - SONET or ATM Add/Drop Multiplexer
  14. 14. COMPETING WIRED ACCESS SYSTEMSFIBER-TO-THE-FIBER-TO-THE-CURB (FTTC) ONU  Switched bandwidth CO HDT  Cost? Analog video?HYBRID FIBER COAX (HFC)  Segmented broadcast bus; FDM/TDM CO FN  Low- Low-cost broadband  Upstream?PASSIVE OPTICAL NETWORK (PON) ONU  Passive outside plant CO HDT  WDM upgrade  Cost? Analog video? Splitter/WDM
  15. 15. ACCESS OPTIONS STRATEGY MENTALITY PREFERRED SYSTEMS Operation Saving HYBRID FIBER/COAX REBUILD NEW Secured FIBER TO THE CURB BUILD SwitchingEmbedded Future PASSIVE OPTICAL NETWORKS ProofNew Entry Low- Low-cost Entry FIXED WIRELESS EARLY MARKET ENTRY Utilize Existing  CABLE MODEM Network  xDSL
  16. 16. EVOLVING Transport - Lightwave - RF Network  Upgrade - Distribution - Quality - Trunk  BroadbandSDV  AM-VSB - Reliability - Bandwidth Terminal - Upstream - Modem - Protocol Operation - Monitoring - Management
  17. 17. EVOLUTION AND REVOLUTION Need Architecture More Evolution/ Revolution Digital Cable Services Modem QualityReliability HFC Linear Lightwave RF & DSP Low-cost lightwave Technology and WDM
  18. 18. Coax to HFCHE
  19. 19. Coax to HFC FN FNHE FN  Increase transport capability  Improve quality and reliability  Challenge for linear lightwave
  20. 20. CHALLENGES OF AM-VSB TRANSMISSION AM- XTR RCVRequirements:CNR 52dB 47dBCTB/CSO -65dBc -55dBc Saleh LimitChallenges: CIR- Linearity - Dispersion - Linearity- Noise - Reflection - Noise- Chirp - Others OMD
  21. 21. RF MODEM TECHNOLOGY I I10110 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
  22. 22. 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 OMD(%) S. Woodward, G. Bodeep, OFC’95
  23. 23. 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 videoRF/(wireless)  2-way communication Front-end Front-  Voice, data, etc  Wireless backhaulingLinear Lightwave Low- Low-cost Maturity Lightwave
  24. 24. EVOLUTION AND REVOLUTION Need Architecture More Evolution/ Revolution Digital Cable Services Modem QualityReliability HFC Linear Lightwave RF & DSP Low-cost lightwave Technology and WDM
  25. 25. 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
  26. 26. SOLUTIONSBandwidth UPGRADE Capacity  Fiber Node Network Segmentation  DWDM Trunk Transport Integrity DOCSIS  High level modulation Modem  Centrally- 103-to-1 mediated MACArchitecture
  27. 27. Fiber Node SegmentationHE FN 1,200 Homes Long cascade coax bus shared by many users (1000s)
  28. 28. Fiber Node Segmentation 300 Homes 300 HomesHE FN 300 Homes 300 Homes  1,200 HHP/FN with 300 HHP/Bus
  29. 29. DISTRIBUTED HEAD-END HEAD- HE FNPrimary Primary Hub HE Ring FN HE  Operation complexity  Cost of CMTS at lower take rate
  30. 30. DWDM TRUNK SH FNPrimary 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-
  31. 31. DWDM TRUNKPrimary Hub Secondary Hub 1.3mmXTR Coarse WDMl 1 x 8 DWDM 1 x 8 DWDMll. . ... . Fiber Node 1.5mm RCVRCV l 1 x 8 DWDM 1 x 8 DWDMRCV lRCV . . . . . .
  32. 32. MODERN HFC NETWORK SH FNPrimary Primary Hub SH Ring SH FN DWDM Transport Segmentation End-to-end Transparency 4X capacity
  33. 33. What If We Succeed?  Bandwidth exhaustion  Transport integrity  Take rate and multiple lines  New services  User behavior  Performance 10000 1000Delay (ms) 100 Life cycle cost 10 v.s. 1 10 20 30 40 50 60 70 80 90 100 Front- Front-end cost Users
  34. 34. ARCHITECTURESTree-and-Branch Broadcast FN Cascaded ???Cell-Based Narrowcast RN Clustered
  35. 35. Mini Fiber Node (mFN) mFN FN mFNPrimary 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
  36. 36. Early Version of an mFN Prototype
  37. 37. Line extender mFN
  38. 38. DELAY COMPARISON 1000 100Average 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
  39. 39. Mini Fiber Node (mFN) mFN FN mFNPrimary Primary Ring Hub mFN FN mFN DWDM PCS Analog Digital TV TV 5 50 500 750 1G 2G  Multi- Multi-service platform
  40. 40. EVOLUTION DemandBandwidth per Customer Take Rate Applications User Behavior Push Fiber Deeper Split Nodes Higher RF Efficiency Time
  41. 41. Fiber Optics for Cable 108 FTTH 107 FTTC (102 HP/node) 106Fiber termination 105 FSA (103 HP/node) 100 ch AM 104 103 102 40 ch AM 86 92 00 06 Broadcast Two-way Broadband
  42. 42. PASSIVE OPTICAL NETWORKSCONVENTIONAL TDM PON 3 2 1 1 LASER 3 2 1 PS • • • BROADCAST BASEBAND PASSIVE • COMMERCIAL TECHNOLOGY • SPLITTERSUBCARRIER (SCM) PON 1 • LASER PS • • BROADCAST PASSBAND • • AVAILABLE TECHNOLOGY 1 2 3 1 2 3 RF RFWAVELENGTH MULTIPLEXED (WDM) PON 1 1 LASER WDM • • • VIRTUAL POINT TO POINT 1 2 • EMERGING TECHNOLOGY 3 •
  43. 43. WIRELESS ACCESS SYSTEMS Cellular - Narrowband/Mobility - High Cost/Poor quality Compete to wireline (voice) Compete Enhanced Services to cableWireless Loop Broadcast PCS Broadband Internet/ WWW Universal Coverage Data - Narrowband: pagers LEO Satellite - Broadband
  44. 44. Broadband Wireless Field Experiment Modem Internet Bell Atlantic Intranet Modem Head-End Platform ServersNSL ‘Switching Center’ Navesink Tower ModemPURPOSE: PSH Office•Explore and extend technology•Demonstrate proof-of-concept
  45. 45. Wireless Propagation Data
  46. 46. Wireless: Tricks to Increase Capacity & Peak Rate What How Advanced Coding Turbo, layered or space-time codes Adaptive Coding Adjust code rate to maximize performance Variety of techniques to combat fading and Diversity and Equalization multipath dispersion Smart Antennas Adaptive processing using antenna arrays Dynamic Resource Allocation Spectrum or timeslots assigned only as needed Minimize transmit power through measurement Power Control and feedback - Orthogonal FDM Advanced Modulation - Wideband-CDMA - M-PSK Introducesignificant complexity in required digital signal processing Rapid progress driven by increases in DSP horsepower (1000X in 10 years)
  47. 47. SUMMARY Emerging technologies, new service opportunities and competition are driving wide variety of access infrastructure choices Cost of photonic components and embedded base keep electronic options (copper pair, coax) for last mile (HFC, FTTC) Desire for passive future-proof outside plant favors PON Fast time-to-market and new service opportunities make wireless alternatives more attractive
  48. 48. “There is no wrong technology, there are only wrong assumptions.”

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