1. The Outlook of Broadband Optical Access Networks Cedric F. Lam Chief System Architect, OpVista Inc. 870 N. McCarthy Blvd, Milpitas, CA 95035, USA +1 (408) 719-6127, cflam@ieee.org

2. Acknowledgement & Disclaimer Acknowledgement Jessica Xin Jiang (Salira Networks) Disclaimer The materials presented here represents my own personal view which could be biased. 3. Telecommunication Networks BackboneMetro ATM (Core) Network Network Channel BankDSL T1 DataDSLAMPOTSISDN DataIDSLG. SIAD HDSLEthernetSONET Headend WDM Cable MeshFCModemetc. HFC Coaxial CMTSFiber Node ONU 1OLT ONU 16 PONPBXT1 100/10 BTGbE100/10 BT Ethernet Router MTU 4. Broadband Access Network Drivers Continuing growth of 1000 Internet and new Voice applications 800 Data Quadruple play: VOIP, IPTV, Broadband Data, 600Total Traffic (Gb/s)Wi-Fi /Wi-Max (backhauling) Storage Area Networks400 Peer-to-peer networking Picture, movie & music sharing200 Network gaming 0 Deregulation of the telecom service market 1990 19952000 2005 2010 Year Telcos and MSOs get into each Coffman and Odlyzko, others marketAT&T Labs, 1997 5. VoD Killer Applicationthe Post-Office Model 4 ~ 8 GBytes per DVD 24 to 48 hours 160 ~ 740kbits per secondFY 2006, Revenue : $997mil, Net Income : $49mil. Source: www.netflix.com 6. Rapid Storage and Processing ImprovementsSource: E. Ayanoglu, UCI 7. VoD EnablersDisk Based Video ServersDRAM Based servers Courtesy: Motorola (Broadbus) High capacity storage Advanced video processing and compression technologies SDTV: ~ 3.5 Mpbs (MPEG-2) HDTV: ~ 8-15 Mbps (MPEG-4) Low-cost and high-bandwidth made available by WDM and Gigabit Ethernet 8. VoD Penetration in the USA Total number of households in the US: 116Millions Source: Forrester Research, 2005 9. Global FTTX Development Fiber to the Premises (FTTP) RBOCs new weapon to compete with MSOs FCC incentive, no need to unbundle the link Joint RFP issued in January 2003 Verizon, SBC (now AT&T) and Bell South Promote interoperability, create economy of scale AT&T: Uverse; Verizon: FIOS NTT GE-PON based FTTH Korea WE-PON (WDM-Ethernet-PON) trial Europe Many carriers have selected G-PON for FTTx 10. US FTTH DeploymentSource: RVA Render FTTH Homes PassesdFTTH Homes Connected(North America) ( North America) 10,000,00095520002,500,0009,000,000 8003000 21420008,000,000 2,000,0007,000,000 609900014785976,000,000 1,500,0005,000,000 410000010110004,000,0001,000,0003,000,000671000 26968462,000,0001619500500,000 0 0 00 0 00 00 001,000,000 00 70 0 0 0 030970000 00 0 35 5 0 00 47 0 46 5 3227001 94 35 721 110 180 18900055 10 22 38 6 7 8 1 213000001 2 2 3 3 4 4 5 5 6 6 7 7 pt 002 pt 03 pt 04 pt 005 pt 06 pt 07 ar 01 ar 02 ar 03 ar 04 ar 05 ar 06700 00 00 00 00 00 00 00 00 00 00 00 0000 , 2 r, 2 t , 2 r, 2 t , 2 r, 2 t , 2 r, 2 t , 2 r, 2 t , 2 r, 2 t , 2S e , 20S e , 20S e , 20S e , 20 M 20 M 20 M 20 M 20 M 20 M 20Se , 2Se , 2,2pt a p a p a p a p a p a p,,,,,, pt Se M Se M Se M Se M Se M Se M SeSe Up to Sept 2007 Growth rate: 2.14mil homes connected 112% annually 9.5mil households passed 300,000 households passed every month 11. TDM vs. WDMONU1 2...16 APON RT 1 2 . . . 161 ONU2 BPON (a) OLT1 2. . . 16 GPON ...Power splitter EPON1 2...16 ONU16 RTONU1 Future1 Upgrade ONU2 (b) OLT2 16...WDM CouplerONU16 12. Power Splitting TDM PON Infrastructure Analog video overlay 1.55m optional Downstream 1.49mONU 1 PBXUpstream1.3m>1:16T1 central office 10/100BASE-T BackboneOLT 1OLT OLT 2Network switch OLT 3PS OLT 4ONU 1610 ~ 20km Power splitter remote node Single fiber connection Upstream and downstream signals separated bywavelengths (1.3m/1.49m) Optional 1.55m broadcast analog signal overlay 13. EPON vs. GPON 14. EPON Multi-Point Control (MPCP) ProtocolReport FrameData frames are not shown here! rpt 1 MPCPDU ONU 1 DA 6 octets overhead Ethernet gte1 gte 2 gte 3 gte nrpt 2 ONU 2 SA 6 octets OLT rpt 3Type (0x88-08) 2 octets PSONU 3 Op-code2 octets rpt n 64 Octets ONU NTimestamp 4 octets Bandwidth request and grant are achieved throughMAC Control Paramerters MPCP protocol ... ONU request upstream BW through REPORT frames OLT send BW allocation to ONU using GATE frames Zero PaddingProsFCS4 octets Only standard 802.3 Ethernet MAC frames are usedNew MAC control messages Maximum compatibility with EthernetGATE op-code = 02Cons REPORT op-code = 03REGISTER_REQUEST op-code = 04 Each MPCPDU is a 64-byte Ethernet MAC frame with itsREGISTER op-code = 05 own overheadREGISTER_ACK op-code = 06 OLT sent GATE frames individually addressed to each ONU for BW allocation Large protocol overhead, less efficient use of BWRef:IEEE 802.3ah 15. GPON (GTC) Downstream Encapsulation 125s Gigabit Transport Container (GTC)Frame header (PCBd) DS Downstream Payload US BW mapAlloc-ID Start End Alloc-ID Start End Alloc-ID Start End1 100 3002 400 500 3520 600 UST-CONT1T-CONT2T-CONT(3)(ONU1) (ONU2)ONU(3)Slot Slot SlotSlot SlotSlot100300 400500 520600 Less overhead Media Access Control (MAC) information for ALL ONUs piggybacked into the same frame. ITU-T G.984.3Source: ITU-T G.984.3 16. GPON (GTC) Upstream EncapsulationPLOu PLOAMu DBRuPayload GEM FrameGEMFrame GEM GEM Full frame Frame fragmentheaderfragment headerheader Dynamic bandwidth report piggybacked to upstreamencapsulation. No separate frames used. G-PON Encapsulation Mode (GEM) Support Ethernet frame fragmentation Support encapsulation of other formats More efficient packing of data Native support of TDM trafficSource: ITU-T G.984.3 17. EPON vs GPON Physical LayerEPONGPONDownstream data rate (Mbps) 10001244 or 2488 155, 622, 1244, or Upstream data rate (Mbps) 10002488Payload EncapsulationNative Ethernet GEMTDM Support Circuit Emulation NativeLaser on/off512ns 13ns Upstream burst AGC400ns mode receiver44nsCDR400ns GPON Power control required in GPON to achieve short AGC time High speed laser drivers required for fast on/off time in GPON, difficult to realize EPON Relaxed component requirements (20~30% cheaper equipment) Can even use traditional AC-coupled receiver as EPON burst mode receiver 18. Per-User Bandwidth Fully loaded 32-way split EPONGPONRawDownstream 31.25 78Bandwidth (Mbps)Upstream 31.25 39 / 78Bandwidth Efficiency 72%92%Effective Downstream 22.5 71.8Bandwidth(Mbps) Upstream 22.535.9 / 71.8 US RBOCS dont think EPON meets their future bandwidth requirements To compete with GPON, IEEE started 802.3av 10GbE-PON task force in March 2006 19. Typical Applications Bandwidth Requirements Application BandwidthQoS Video (SDTV)3.5 Mbps Low loss, low jitter, constantbit rateVideo (HDTV)8-15 MbpsSame as aboveTelecommuting 10 MbpsBest effort, burstyVideo gaming10 MbpsLow loss, low jitter, bursty Voice 64 kbpsLow loss, low latency, constantbit ratePeer-to-Peer100 kbps 100 Best effort downloadingMbps 100Mbps Download an 8GB DVD movie in 10 minutes Blue Ray: 25 to 200GB per disk 20. Changes in Network TrafficDaily traffic volume at a Google data center by hoursWhen Google bought YouTube!D. Lee, OFC 2008, paper OThB1 Traditional web surfing is user active, network passive Video is user passive, network active. 21. Statistical Multiplexing GainPerception time 30 Mb/sequivalent circuit rate10 Mb/s B avg rate avg rate detail500 10Mb/s surfers sharinga 30Mb/s channel(40 kb/s average) t Web-surfing Poisson packet arrival distribution Equivalent circuit rate The perceived circuit rate experienced by users 500 users with average usage of 40kb/s Each user perceives as if he/she has 30Mb/s (500x40kb/s) = 10Mb/sN.K. Shankaranarvanan, ATT, User-perceived peformance Proc. ICC, June 2001N.J. Frigo, Fiber to the home: niche market OFC 2004 Tutorial 22. VoD Bandwidth Characteristics Video streams characteristics High bandwidth usage Highly asymmetric Uniform and steady packet arrival rate Video consumptions are highly peaked during primeviewing hours or special events such as soccer games. Statistical multiplexing gain no longer validVideo Peak viewingusage rate hours Hour 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 of day 23. How Much Bandwidth is Needed? US Population Statistics (US Census Bureau http://www.census.gov) Total Population: 300mil, Number of households:116mil Average 2.6 people per household 24 ~ 45Mb/s bandwidth per household Enough for everyone at home to watch a different HDTV at the same time (without counting background download jobs, which can take advantage of statistical multiplexing). Good before another killer application emerges GPON will be able to support fully loaded VoD BW requirements and have room to grow EPON have barely enough BW when VoD takes off. Shrink the service group, 1:8 ONUs per OLT Develop 10GbE PON 24. 10GbE-PON IEEE 802.3av, started March 2006DownstreamUpstreamSymmetric 10Gb/s10Gb/s Asymmetric 10Gb/s1Gb/s Backward compatible with 1G E-PON WDM overlay Dual rate OLT receiver 25. Symmetric and Asymmetric 10Gb-EPON Operation10/1G Asymmetric 10/1G AsymmetricONUOLT 10G Rx10G Tx10G DS (1.577/1.590m)1G Tx1G Rx 1G US 1.310m 1:16 10G Symmetric 10G Symmetric ONUOLT10G Rx10G Tx 10G DS (1.577/1.590m)10G Tx10G Rx 10G US 1.270m 1:16To be finalized by IEEE802.3av task force. 26. 10Gb-EPON Optical Spectrum Management - 1Upstream TDM Overlay1G ONUOLT1G Rx 1G DS (1.490m)WDM 1G Tx1G Tx 10G DS (1.577/1.590m) 10G Tx WDM10G ONU (Asymmetric)1G US 1.310m 1G/10G Rx10G Rx 1:16 WDM1G TxDual rate OLT receiver May incur 3dB splitting loss 10G ONU (Symmetric) at OLT10G RxWDM10G Tx To be finalized by IEEE802.3av task force. 27. Dilemmas of 10GbE-PON Split Ratio 1:16 1:321:64 Effective BW (Mbps)545272.5 137 Higher splitting ratio desirable to achieve better cost sharing and more efficient use of available BW 1:64 or 1:128 (recall that each HH requires only ~45Mb/s BW) May need to extend coverage distance for bigger share group size (e.g. up to 60km) Further worsens the physical challenges for 10Gb/s PON signal transmission 28. 10GbE-PON Transmission Challenges Dispersion Effect (increases as square of bit-rate) EML (narrow modulated line width) EDC may be needed at ONU receiver Power Budget Extension 9.1dB more theoretical received power requirement compared to EPON (8B10B GbE vs. 6466B 10GbE coding) Split Ratio1:321:641:128 Loss (dB) 15 18 21 Fiber length 20km40km60km Loss (dB) 4 8 12 15 to 27dB more power budget required from OLT to ONU Penalties (dispersion, fiber non-linearity) Fiber non-linearity Limit power budgets 29. Technologies for 10Gb-EPON Transmission APD3dB Improves sensitivity by7~8dB EDC 2~3dB gain FEC 7dB Improves power budget by3~5dB F. Chang, 10G EPON Optical Budget Considerations http://grouper.ieee.org/groups/802/3/10GEPON_study /public/july06/chang_1_0706.pdf4.4dB 30. Technologies for 10Gb-EPON SOA 15dB gain Operate at all Planner technology (mass manufacture) Compact size, (multi- channel packaging available) Beneficial for burst data Burst data SOAEDFAL. Spiekman, IEEE802.3av meeting, Nov, 2006, Dallas, Tx http://grouper.ieee.org/groups/802/3/av/public/2006_11/3av_0611_spiekman_1.pdf 31. SOA / EDFA in 10Gb EPON10Gb/s ONU 1 Gb/s TxBooster PIN / 10Gb/sWWAPD OLTEML SOA/D PS D EDFA MMDML/ EML 10Gb/s Rx APD+EDC SOAPreamp Integrated Solution10Gb/s ONU 1 Gb/s Tx PIN / 10Gb/sWWAPD OLTEMLSOA D PS D MMDML/ EML 10Gb/s RxSOA APD+EDCKeep the ONU simple !SOA may be used as data modulator 32. Fiber Non-linear Effect (SRS)1490nm (pump) penalty 10G 1550nm (10G DS)1. S. Tsuji, Issues for wavelength allocation, IEEE802.3av meeting, Sept. 2006 http://grouper.ieee.org/groups/802/3/av/public/2006_09/3av_0609_tsuji_1.pdf 2. S. Ten and M. Hajduczenia, Raman-Induced power penalty in PONs using order approximation, IEEE802.3av meeting, Jan 2007, http://grouper.ieee.org/groups/802/3/av/public/2007_01/3av_0701_ten_2.pdf 33. Fiber Non-linear Effect (SBS)Limits transmitted power S. Ten, SBS degradation of 10Gb/s digital signal in EPON: experiment and model IEEE 802.3av meeting, Jan 2007 http://grouper.ieee.org/groups/802/3/av/public/2007_01/3av_0701_ten_1.pdf 34. WDM-PON S. Wagner et al, JOLT, 7, 1759 (1989) WCO D M PS PON advantages Subscriber buys upgrades passive & future proof Expensive components Point-Point connections WDM mux-demux cost still high Privacy / Security accurate wavelength lasers required Simultaneous Service Diversity temperature stability 35. Waveguide Grating Router INPUT OUTPUT 1 W1 2 G2 33 4 R4 RemoteI B1 B2 B3 Nodeuser 1 IntensityI B1 B2 B3 B1 B2 B3 user 2WGR...I B1 B2 B3 user nAlso called Arrayed Waveguide Grating (AWG), phase array orDragone Router Fabricated on Silicon 36. WDM on WDMW W...D GM RW...DM +W ...D+ MRef: Iannone, et al., PTL 8, 930 (1996), Frigo, et al., OFC'97 PD24 37. Athermal AWG Devices 38. Athermal AWG 39. Injection Locking of Upstream LaserSpectrum before lockingCourtesy: Novera Optics 40. Reflective SOA Courtesy of ETRI and Korea Telecom 41. Planar Lightwave Circuit - ECLCourtesy of ETRI and Korea Telecom 42. WE-PON (WDM-E-PON) ~ 1000 users per feeder fiber (32 x 32 TDM)WDM-PON used for metro backhauling WDM is an efficient way to increase splitting ratioCourtesy of ETRI and Korea Telecom 43. Conclusion Demands for bandwidth continue to drive broadband optical access network development Digital and packetized video becomes the killer application Bandwidth usage pattern is changing, statistical multiplexing no longer holds for new broadband applications (VoD) FTTx a personal view: GPON delivers the right FTTH BW for the next a few years. EPON offers the initial cost advantage FTTx development is good for economy 10GE-PON and WDM-PON developments will create new component industries Dont let our lack of imaginations limit the development of broadband access networks FTTx research took 20 years to get to todays deployment stage Bandwidth is always good and will finds its applications to benefit human societies. Question: Are there any other better ways to make a PON? 44. Thank you!