WDM-PON 2005. 1. 27. 김병휘
2 Contents FTTH WDM-PON T-PON with PLC-ECL R-PON with RSOA UCL (TO-CAN with TEC) WDM/SCM-PON
FTTH Perspectives 3 C&B Type Technology 2002 2003 2004 2005 2006 2007 2008 2009 AON (FTTC) Overlay TDM-PON In-Band WDM-PON 2010 Speed per Channel Transceiver 155/622 Mbps TO-CAN Type 1.25 Gbps 2.5 Gbps * PLEC: Planar Light & Electronic Circuit Optically Hybrid Type (PLC) 10 Gbps O-E Hybrid Type (PLEC*) Market NTT, 동경전력 180 만 NTT, 소프트뱅크, 동경전력 3000 만 Verizon,SBC100만 Verizon,SBC 1300만 Verizon,SBC 3000만시장 KT시범 KT 175만확대 NCA 시범홈네트워크시범 ETRI 시범건설업체 ( 특등급 )
FTTH 현황 - 세계 4 최근 FTTH 기술은인터넷접속속도증대차원을벗어나기존인터넷서비스에 VoIP, IP-TV 를결합하는 TPS 가새로운통신서비스모델로부상 미국은 FCC (Federal Communications Commission) 연방통신위원회의 UNE (Unbundling Network Equipment) 유보정책발표를전기로최근 Verizon, SBC 등 RBOC 들이 FTTH 투자를획기적으로증대 Verizon 은 2005 년까지 300 만회선의 FTTH 구축예정 ( 당초 100 만회선 ) SBC 는 2007 년까지 1800 만회선의 TPS 서비스망구축예정 (20~25Mbps 급서비스제공하는 FTTN (Fiber To The Neighborhood) 포함 ) 2007 년까지 1300 만회선, 2009 년까지 2900 만회선의 FTTH 구축예측 (RVA 의 FTTP/FTTH 2004/2005 예측자료, 2004.11) 일본은본격적인 FTTH 시대돌입 2004 년 8 월현재 160 만회선돌파, 전체광대역가입자 1,590 만의 10% 수준 FTTH 가입자는 1 년전에비해약 4 배증가, 최근월 10 만회선씩증가 국내는 KT 가 2009 년까지 175 만회선의 FTTH 구축계획발표 LG 전선은파키스탄에 FTTH 설비 1500 만달러수출계약체결 광주시는 2 만회선의 FTTH 상용화계획확정 (2005 년 ~2009 년, 1194 억원투자 )
FTTH 현황 - 미국 5 FTTH 가입자급증 2004 년 9 월현재 97 만가입자 2004 년 3 월의 19 만가입자수준에서급증배경은 Verizon 사업에기인 1,200,000 FTTH Homes Passed 1,000,000 970,000 800,000 600,000 400,000 200,000 0 19,400 180,300 189,000 110,000 72,100 35,700 2002 2003 2004 2005 2002 2002 2003 2003 2004 2004 2005 2005
FTTH 현황 - 일본 2004 년 8 월현재가입자수 160 만 매월 10 만가입자증가 총무성의 e-japan II 계획 (2003. 7) 2005 년광섬유에의한초고속인터넷접속 1,000 만가입자목표 NTT 의중기경영계획 (2004. 11) 2010 년 3,000 만가입자목표 ( 총 5 조엔투자 ) 2004 년 10 월부터소프트뱅크의 FTTH 사업참여로경쟁가속 EPON 링크 1 Gbps 를 32 가입자가공유하는방식으로서비스제공 100 Mbps VDSL 병행 경제성이높은공동 / 집합주택시장은경쟁치열, 투자비가많이소요되는주택지역은 NTT 가주도 (81.8% 점유 ) 6
FTTH 현황 - 유럽 스웨덴이탈리아네덜란드프랑스 가입자 29 만 (2004. 12) 16 만 (2003. 12) 8 만 [2004. 6) 5 만목표 (2004. 8 시작 ) 방식 AON AON AON AON 서비스 10 Mbps 음성, DATA, 방송 10 Mbps 음성, DATA, 방송 10 Mbps 음성, DATA, 방송 10 Mbps 음성, DATA, 방송 특징 방송서비스추가과금 투자 2 년만에흑자전환, 방송서비스가입자증가 2007 년까지 45 만가입자구축 PBC : 지자체포설, CATV SO 운용, 3 년내 5 만가입자확보 출처 : ITU-T ASNA Workshop 2004, FastWeb 7
WDM-PON as a FTTH Solution Avoid Inventory Problem Wavelength Tunable Colorless Reduce Optical `Cost 전용선 (Premium Users): Less than $[VDSL] x 10 Public Users: Less than $[VDSL] x 5 All-Passive Packaging Make Reliable to Environmental Changes 8
WDM-PON Requirements (Example) 9 항목 기준값 채널수 32 채널당전송속도 1.25Gbps (1000BASE-X) 항목 온도 ( C) OLT 0 ~ 60 RN 맨홀 -20 ~ 70 RN 외기 -30 ~ 60 ONT 실내 0 ~ 60 ONT 실외 -20 ~ 60 채널당출력광세기 광선로손실 최대색분산 전송거리 채널당입력광세기 광전송성능감시 ( 파장제어 ) 0 dbm 7 db 17 ps/nm 20 Km -25 dbm 0.01 nm/min 파장변화율을 1 % 의오차이내추적
WDM-PON Types 10 Central Office Injection Locking 방식 T-PON with PLC-ECL C-band EDFA L-band EDFA 가입자 Central Office 가입자 FP-LD PD 필터 필터 FP-LD PD PLC-ECL PD 필터 필터 PLC-ECL PD Central Office CW-RSOA 방식 DFB-LD R-PON with RSOA R-SOA PD 필터 필터 DFB-LD 1310 nm 대역 필터 1550 nm 대역 필터 가입자 R-SOA PD Central Office SML PD R-SOA PD DFB-LD DFB-LD
11 T-PON with PLC-ECL
FBG-ECL, WBG-ECL (all active alignment) light output waveguide gain medium (R-LD) Bragg-grating 26.00 WBG Protector CL5.60 10.00 8.90 12.70 2.54x6=15.24 20.83 30.00 1.00 PIN : 7-0.5 x 0.25 R0.65(Glass sealing) 1.00 8. LD(+) 9. LD(-,) 10. Case GND 11. N/C 12. N/C 13. N/C 14. N/C 7. M-PD(+) 6. M-PD(-) 5. Case GND 4. Thermistor 3. Thermistor 2. TEC(+) 1. TEC(-) LD ECL with fiber Bragg grating 12 ECL with Waveguide Bragg Grating TEC Optical fiber
FBG-ECL BTB 20 km BTB(w/ AWG) 20 km(w/ AWG) 622Mbps, after SMF 20km transmission 13
14 WBG-ECL 10 Output Power (dbm) 0-10 -20-30 -40-50 -60-70 1540 1542 1544 1546 1548 1550 1552 1554 1556 1558 Wavelength (nm) BTB 20 km 1.25Gbps, after SMF 20km transmission
Tunable PLC-ECL: motivations DFB-LD spec + λ-tunablity structure players cost tuning range output power Current tunable source SG-DBR, DFB-array, Agility, New focus, $5000 ~ $10000 Full C-band, C+L band 0 ~ 13 dbm Tunable PLC-ECL tunable Bragg grating none < uncooled DFB-LD 200GHz, 16ch (26 nm) -3 ~ 0 dbm Linewidth 1 ~ 25 MHz - SMSR tuning speed λ-locking packaging modulation transmission distance 30 ~ 45 db ~ msec included all active alignment external modulation > 100 km > 30 db ~ msec none all passive alignment 2.5Gbps direct modulation < 20 km Over-spec. for access networks lower spec. with lower price 15
PLC-ECL Key features Waveguide structure Thermally tunable Bragg grating Spot-size converter LD Package super high index contrast =1.5%, 4.5 x 4.5um, polymer material dn/dt ~ -1.8x10-4 /K T=200 deg, λ tuning ~30nm far-field angle < 15 deg. All passive alignment LD: flip-chip bonding fiber: V-groove integrated standard 14-pin butterfly package Chip dimension W x H = 5 x 10 mm 2 16
PLC-ECL Mask Layout SSC-LD 17 LD section SSC section
18 PLC-ECL Mask Drawing ~ 84 chips on 4-inch Si wafer
19 PLC-ECL 14-pin BTF package Sample PLC-ECL chip 사진 (LD 집적 )
20 PLC-ECL 특성 - 파장가변 0-5 #9-13 optical power [dbm] -10-15 -20-25 -30-35 -40 1546 1548 1550 1552 1554 1556 1558 wavelength [nm] single-mode lasing output power > -5 dbm SMSR > 30 db 파장가변 ~ 14 nm
21 PLC-ECL 특성 - 1.25Gbps, 20km 전송 20km back-to-back
22 PLC-ECL 특성 - 파장별전송 (1.25Gbps) #9-13 1557.24 nm After 20 km 1558.15 nm Device temperature: 13.1 o C Bias : 60 ma ER : about 8 db
Technical Issues in PLC-ECL Issues Current Methods Main problems Our solutions Bragg grating 1. Two-beam Interfere 2. Phase Mask ebeam Writing Difficult to write grating in the predetermined area according to design Writing time is too long 1. Master phase-mask 2. nano-imprinting method 3. Higher order grating Wide Tunability Single WBG for 26 nm Tuning Thermal stability of polymer and metal heater 1. Parallel or serially connected WBG s 2. Dual heaters 3. Thermal blocking layer LD Coupling End Butt Coupling Very good spot-size converter must be integrated with LD. Far field angle < 15 deg. Etched facet LD (SSC-LD far-field angle ~ 20 deg) (Chip cost is higher than DFB-LD) Low-cost Package 14-pin Butterfly Price: 50~60$/Butterfly Case (too high cost) 1. mini-dil package 2. Plastic butterfly package 3. Other types of package 23
24 PLC-ECL Improvements monitor PD laser diode heater optical fiber Bragg-grating Si substrate Improvements 0ne-piece chip ( 5 mm x10 mm ) 평판형도파로와의효율적인광결합방식을이용한 SSC-LD far-field angle 조건완화 (SSC-LD 수율향상, far-field angle:12.5 20 deg.] optical tap coupler 를이용한출력파워 monitoring 기능포함 양산화에용이한저가의 WBG 제작 광섬유와광결합하는영역의평판형도파로에 SSC 공정을도입 (all passive 정렬방식사용 )
25 R-PON with RSOA
Amplitude Squeezing OUPUT POWER (dbm) 0 1 0 1 0 RSOA 로입력된하향신호 Modulation with upstream data RSOA 의 saturated gain 을통과한뒤의하향신호 상향신호로변조된 RSOA 출력 Saturation Input power INPUT POWER (dbm) Optical gain (db) 14 12 10 8 6 4 2 0-2 -13-12 -11-10 -9-8 -7-6 RSOA output power (dbm) 26 하향 상향 Eye Diagrams
27 RSOA 전송실험 Setup λ= 1550 nm DFB-LD (Nortel) PPG (Adventest) 2.5 Gb/s 1.25 Gb/s NRZ 100 GHz spacing AWG Current = 60 ma 70 ma 80 ma RSOA 90 ma PPG (Anritsu) Driving Amp. (JDS Uniphase, VM10EMD) 1.25 Gb/s NRZ DCA SMF 20 km DCA : Digital Communication Analyzer PPG : Pulse Pattern Generator BERT : Bit Error Rate Tester RECEIVER BERT (Anritsu)
28 RSOA 실험결과 - BER (BTB) @Pin= Pin=-10 dbm, BTB with 1.25 Gbps downstream with 2.5 Gbps downstream downstrean extinction ratio CW 3 db 4 db 5 db downstrean extinction ratio CW 3 db 4 db 5 db
29 RSOA 실험결과 - BER (20km) @Pin= Pin=-10 dbm, SMF 20 km with 1.25 Gbps downstream with 2.5 Gbps downstream downstrean extinction ratio CW 3 db 4 db 5 db downstrean extinction ratio CW 3 db 4 db 5 db
30 PLC-RSOA Improvements RSOA chip 결합렌즈 RSOA data PD monitor PD optical fiber Si substrate Improvements 0ne-piece BiDi chip ( 5 mm x10 mm ) SSC-RSOA 사용 온도특성 : 0 ~ 60 o C 편광특성 : 1 db 이하 광섬유와광결합하는영역의평판형도파로에 SSC 공정을도입 (all passive 정렬방식사용 )
Comparison with NTT 31 쭈꾸바쭈꾸바 2003. 11. 2003. 11.
32 UCL (TO-CAN with TEC)
33 UCL Structure Bracket : Al, 7 x 7x 10mm with dia 5.6mm hole TO-56 stem : steel, 열원 :0.2x1.0x300um stripe( 발열량 30mW) Dia. 5600umx1200um LD chip : InP, 100x400x300um Heat sink : AlN, 250x700x400um 후면축소 TEC 상하판 : Al2O3, 1x12x15mm 정면확대 header : steel, 1000x1500x1400um Heat sink : Al, 3 x 50 x 50mm
34 UCL λ Stability on Temperature Change C-band UCL 광원의온도에따른중심파장변화 1546.8 1546.4 1546.0 1545.6 0.8nm ch_3=1546.12nm wavelength [nm] 1545.2 1544.8 1544.4 1544.0 1543.6 ch_2=1544.53nm ch_1=1542.94nm sample#1_c-band sample#2_c-band sample#3_c-band sample#4_c-band sample#5_c-band sample#6_c-band 1543.2 1542.8 1542.4-20 0 20 40 60 temperature[ o C]
UCL Power Stability on Temperature Change C-band UCL 광원의온도에따른출력광파워변화
36 UCL 전송특성 - BER BER Plot @ 25 C actual temperature Set temp: 25 C Set temp: 30 C Set temp: 35 C Set temp: 40 C
WDM-PON Demo Setup (2004. 12. 13) Video Camera User Premises Central Office CMB Cable TV ONUs WDM MUX & DeMUX RSOA PLC-ECL RSOA Subscriber 1.25 Gbps L2/L3 Switch WDM MUX & DeMUX OLT OTRx PLC-ECL WDM Link OAM PLC-ECL Subscriber 1.25 Gbps 20 km 상향 / 하향 37
Automatic Wavelength Alignment OLT RN @ MDF Tracking Tx Tx Tx 1542.14nm 1543.73nm 1545.32nm 20km Rx ONT Monitoring MPU Monitoring Rx Rx Rx 1542.14nm 1543.73nm 1545.32nm 20km WDM MUX/DMX Tx MPU Tracking 38
39 WDM/SCM-PON
WDM/SCM-PON Structure IDF CO ONT STRx PD LD 10 LD Array PD STx STx SRx 100M VoIP CATV Array SRx VoD 32 x 1.25Gbps WDM 10 SCM channels per wavelength 100 Mbps / SCM channel 20 Km transmission distance 1000 users on 4 fibers STx: : SCM Tx SRx: : SCM Rx 40
41 SCM TRx SAW IF BPF LD SMF 20km Detector 305MHz 1000 1450MHz ~ SCM Modem PLL Tunable PLL 305MHz 1000~ 1450MHz SAW IF BPF PD SMF 20km Detector 30MHz BW / SCM 채널 50MHz BW include guard band / SCM 채널 10 SCM 채널전송소요대역폭 500MHz (50MHz 10 채널 ) Tunable SCM carrier generation 600 ~ 1200 MHz 송수신 SCM 신호모니터링기능
42 OBI (Optical Beat Interference) ONT δν :optical source freq. difference Mod. OLT LD1 f 1 δv PD OBI Σ 1 2 N 1 : N Splitter LD2 Mod. f 2 Optical power spectrum Signal 1 Signal 2 v FWHM vfwhm Frequency i( t) ~ Pinput ( t) = E1( t) + E2( t) 2 2 = E1( t) + E2( t) + 2Re 1 1 2 3 1 3 1 4 4 2 SCM signal 1 SCM signal 2 2 [ E ( t) E ( t) ] OBI noise 2 4 4 3 Receiver N Photo detector SCM signal Electrical power spectrum δ v δ v = v1 v2 v = 2 v OBI OBI FWHM v OBI Frequency DC
OBI Reduction by Spectral Broadening Optical power spectrum δλ Photo detector Electrical power spectrum δλ λ1 λ 2 Frequency SCM signal OBI f1 f M Frequency Linewidth of 100GHz Linewidth of 2600GHz BPSK QPSK BPSK QPSK 16QAM 16QAM 64QAM 64QAM (a) (b) Maximum number of subscribers versus a range of linewidths (a) from 0 to 300GHz (b) from 0 to 3000GHz @ modulation index / subscribers = 100% 43
OBI Reduction by Wavelength Separation Photo detector Optical power spectrum Electrical power spectrum SCM signal f1 f M δλ λ 1 δ λ OBI λ 2 Frequency Frequency Limited by passband of 100GHz BPSK QPSK Limited by passband of 2600GHz BPSK QPSK 16QAM 16QAM 64QAM 64QAM (a) (b) Maximum number of subscribers versus wavelength differences of any two lasers in the network (a) from 0 to 20GHz (b) from 0 to 500GHz @ modulation index = 20% 44
Comparison of OBI Reduction Schemes Mod. Formats BPSK/ QPSK 16QAM 64QAM Spectral Broadening DWDM (100GHz passband) 4.7 CWDM (20nm passband) 21.4 2.9 12.1 < 2 7.2 Wavelength Separation DWDM (100GHz passband) CWDM (20nm passband) 15.7 22.3 9.6 12.2 5.8 6.8 45
46 WDM/SCM Demo Setup WDM-PON x 10 채널 SCM 채널당 100Mbps 속도 ONTs OLT CMB Cable TV SCM 가입자 100 Mbps 20 Km SCM OLT SCM 채널모니터링 X 10 SPLITTER 100Mbps 1.25Gbps SCM 스펙트럼모니터링 WDM MUX/DMX 광스펙트럼모니터링
47 SUMMARY T-PON (Tunable WDM-PON) Planar Lightwave Circuit External Cavity Laser 16nm Wide Range Tunable (to be improved to 26nm @ 2005) 파장가변 DWDM 광모듈을초저가화 20% yield (to be improved to 30% yield @ 2005) R-PON (Reflective WDM-PON) Reflective Semiconductor Optical AMP Simplest Transmission Algorithm using Modulated Optical Signal UCL (Utility Cooled Laser) Low-cost DWDM Optical Source Module Good for FTTP due to Inventory Problem WDM/SCM-PON A Practical OBI Solution Employed 10 SCM Channels per Wavelength (100Mbps/user) A Good Candidate for 100Mbps-per-user Market
48 Conclusion 초기시장 시장성숙 DOCSIS: data over cable service interface specifications Still Enough Time to Develop better technologies Put as many technologies into competition as possible