Fiber Broadband Network Systems Hai-Han Lu ( 呂海涵 ) hhlu@ntut.edu.tw National Taipei University of Technology Institute of Electro-Optical Engineering
Outline Broadband Introduction Principles CATV / Fiber Internet Integrated communications DWDM High speed High capacity
Broadband - CATV CATV means that use coaxial cable to transmit TV programs CATV can compensate for insufficient air channels CATV is a kind of local communications Fiber brings a lot of benefits in Data Communication also in CATV systems
History The origin of CATV can be traced back to 1940s in America In suburban areas Obstacles Geography Architectures Using Electric Cord Community Antenna Television (CATV) Cable Television
History about TAIWAN CATV Years 1961~1971 1971~1981 1981~1991 1991 1998 2003/04 Program providers adopt CATV to overcome complex geometric landscape. Licenses had been issued to commercial CATV organization. Cable TV system workgroup had been established during this time in Executive Yuan CATV protocol was completed and sent in Executive Yuan to await approval. DTV was under monitored and test-run DTV/CATV History
Satellite CATV Head End Program Provider Transmit Path
System NTSC National Television System Committee PAL Phase Alternation by Line SECAM SEquentiel Couleur A Memoire
World Wide CATV NTSC PAL SECAM
Frequency Distribution Down-stream Up-stream Analog broadcast video Digital video 0 100 200 300 400 500 600 700 800 900 Up-stream 6 MHz 5~30 MHz Down-stream. Analog 50~550 MHz 170 180 190 200 210 220 Digital 550~750 MHz Frequency (MHz)
Frequency Distribution Frequency fv fc fa 3.58 MHZ 4.5 MHZ 6 MHZ
Tree Architecture Suburban.... Splitter LAN. Splitter Splitter Central Office Easy to build Need many amplifiers Metro
CATV Transmit System MTV MTV LD LD Trunk Amplifier Directional Coupler Distribution Line VCR VCR Satellite HEAD END Power Supply Bridger Amplifier Feeder Line Tap Line Extender Splitter Tap Drop Line Home Home Home Home
Cable/Fiber Internet Cable/Fiber Internet
Cable Internet Television Cable TV System Cable Splitter Cable Cable Modem Personal Computer
WWW internet access Access Speed Image Image Video Video (2 MB) (16 MB) 72 MB 4 GB Teleph. 56 Kb/s 4.76 min 38min. 2.86 hr 160 hrs Modem ISDN 128 Kb/s 2.38 min 19min. 1.43 hr. 80 hrs T1 or 1.5 Mb/s 11 sec. 1.4min. 6.6min. 6 hrs ADSL Cable 10 Mb/s 1.6 sec. 13 sec. 58 sec. 53 min. Modem (Shared) DS3 45 Mb/s 0.36 sec. 2.84 sec. 13 sec. 12 min. Gigabit 1 Gb/s 0.016 0.13 sec. 0.58 32 sec. Ethernet sec. sec.
WWW internet access Access Technologies Teleph. Modem ISDN T1 or ADSL Cable modem DS3 Fast Ethernet Gigabit Ethernet Speed 56Kb/s 128Kb/s 1.5Mb/s 10Mb/s(shared) 45Mb/s 100Mb/s 1.25Gb/s Transmission Media Twisted Pair Twisted Pair Twisted Pair Coax Cable Cable / Fiber Cable / Fiber Fiber
Multimedia Service DTV PPV MPEG Digital TV Digital TV Information EPG ITV MOD VOD MPEG4 VoIP MHP Data on demand Web Site Broadband Internet Internet
Coaxial Cable vs. Fiber aluminum Central conductor Magnetic lines RF Signal Coaxial Electric lines Jacket Core 60 60 Hz Hz AC AC Cladding Cladding Cladding Fiber Core Core
Why use Optical Fibre? First Applications Immune to Electrical Interference No radiated signals Next Occupied less duct space Next Longer distances Now: Very low cost Very high information capacity Multi-copper pair cable Fibre cable Coax cabl
How far light goes greatly impacts long distance network economics Tx optical fiber Rx ATTENUATION comes from fiber, connectors, splices etc Power of the optical signal sent Attenuation Dispersion Fiber quality A fiber has a loss which represents the power used to to travel a certain distance (typically < 0.25 db per km) Sensitivity of the receiver However, sending more power is not necessarily the solution to greater span length (due to fiber non linearity)
Dispersion behavior: different speed Along the Fiber λ
Different behavior: different speed Over short distances Over long distances
Disadvantages of CATV Systems Using many amplifiers Reduce signal quality Not easy to repair Have EMI distortion Use Tree-Branch Structure Not easy to expand
Advantages of Fiber Optical CATV Systems Fiber Filter Transmitter EDFA EDFA Receiver Direct/ external modulation Easy to Upgrade High P out Medium NF Easy to repair reliable Repeaterless to remote pumping Low NF High gain PIN/ APD Transmitter EDFA EDFA EDFA Receiver Direct/ external modulation High P out Medium NF High P out High gain Low NF P in ~ -15dBm L n ~ 30dB PIN/ APD L 1 ~ 20dB J. W. Liaw
Compare Between FTTH and CATV Transmission media Transmission distance Service items Transmission method Fiber To The Home Fiber Low loss Broadband Can overcome EMI More than 20Km Video, Audio, Telephone, FAX Dual direction Coaxial electric cord 410m/repeater Video CATV Single broadcast
FTTH / FTTC / HFC for Broadband Access
HFC Systems 1.319µm Nd-YAG Head End LiNbO 3 Mod. 1.3µm DFB- LD 1 x N coupler 1 x N coupler 1 x N coupler Fiber node Coax/ ADSL node node 1.55µm DFB- LD LiNbO 3 Mod. EDFA 1 x N coupler 1 x N coupler EDFA AM-VSB Hybrid Digital /Analog
DWDM DWDM
DWDM Systems for Higher Capacity Single-Wavelength System Upgrade Tx Fiber Rx Multi-Wavelength DWDM System Tx 1 Tx 2 Tx 3 Tx 4 Fiber Rx 1 Rx 2 Rx 3 Rx 4
TDM and WDM Basic Concept TDM More People per car WDM More lanes
TDM Signal Code from a single-laser wavelength Mux fiber TDM Signal Code from multi-laser wavelengths Mux fiber WDM
Why DWDM? Data Channel 1 Data Channel 2 Data Channel 3 Data Channel 4 Optical Fiber WDM channels multiplex data signals into a common optical fiber Maximizes optical fiber use Capacity growth over existing fibers Reduces costs to to lease/deploy additional fibers Equipment cost sharing Multiple data channels transmitted over common equipment Existing electronics used Bit rate insensitive Permits future TDM upgrades to to maximize fiber capacity Modulation format independent Multiple data formats transmitted in in parallel
High-Capacity Systems (TDM+DWDM ) OC-Level OC-3 OC-12 TDM OC-48 OC-192 OC-768 OC-48 4 OC-48 16 DWDM OC-192 8 OC-192 32 OC-768 40 Line Rate 155 Mb/s 522 Mb/s 2.5 Gb/s 10 Gb/s 40 Gb/s 10 Gb/s ( 4 2.5 Gb/s) 40 Gb/s (16 2.5 Gb/s) 80 Gb/s ( 8 10 Gb/s) 320 Gb/s (32 10 Gb/s) 6 Tb/s (40 40 Gb/s)
DWDM Wavelength Plan C BAND L BAND L band (1560 to 1600nm) more than doubles the existing window! 196.1 1528.77 195.9 1530.33 195.7 1531.90 195.5 1533.47 195.3 1535.04 195.1 1536.61 194.9 1538.19 194.7 1539.77 194.5 1541.30 194.3 1542.90 194.1 1544.50 193.9 1546.10 193.7 1547.72 193.5 1549.32 193.3 1550.92 193.1 1552.52 192.9 1554.13 192.7 1555.75 192.5 1557.36 192.3 1558.98 192.1 1560.60 (THz) (nm) ITU-T wavelength grid Optical Channel Plans: 50GHz, 100GHz or 200 GHz spacing? Grid allows lasers and filters to be built to a common specification
WDM: Uni- and Bi-directional λ 1, λ 2... λ N Tx 1 Rx 1 Tx 1 λ 1, λ 2... λ N Rx 1 Tx 2... Amp Rx 2... Tx 2.. Tx N Rx 2.. Rx N Tx N Rx N λ 1, λ 2... λ N Rx 1 Tx 1 Rx 1 Tx 1 Rx 2... Tx 2... Rx 2.. Rx N Tx 2.. Tx N Rx N Tx N Uni-directional D-WDM 2 fibers needed for first channel Bi-directional D-WDM Only 1 fiber for send/receive One bi-directional amp used Bi-directional and uni-directional solutions are supported
2 3... MATRIX SX-16 78 (NTSC) 79 80.. 116...... Push-pull Preamplifier Push-pull Preamplifier DFB LD1 1560.6nm DFB LD2 1559.0nm λ 1 λ 2 2dBm 2dBm DWDM MUX 13.9dBm/λ 1 ~λ 3 EDFA-Ⅰ A Hybrid DWDM System Pattern Generator 256-QAM Modulator 8ch DFB LD3 1557.4nm λ 3 2dBm 0dBm/λ 1 ~λ 3 10.8dBm /λ 1 ~λ 3 2.8dBm /λ 1 ~λ 3 14.2dBm /λ 1 ~λ 3 6.2dBm /λ 1 ~λ 3 40.2Mb/s 2x1 Coupler EDFA-Ⅱ 40km LEAF 40km LEAF OC-48 Tx 1554.1nm λ 4 0dBm -11.2dBm /λ 4 ~λ 7-19.2dBm /λ 4 ~λ 7-7dBm /λ 4 ~λ 7-15dBm /λ 4 ~λ 7 OC-48 Pattern Generator OC-48 Tx 1552.4nm OC-48 Tx 1550.9nm λ 5 0dBm λ 6 0dBm DWDM MUX -2dBm /λ 4 ~λ 7-8.1dBm /λ 4 ~λ 7 VOA HP-8591C RF BPF (50~550MHz) RF BPF (550~750MHz) Analog Rx Analog Rx λ 1 VOA λ 2 1.2dBm OC-48 Tx 1549.3nm λ 7 0dBm 256-QAM Error Detector 256-QAM DeModulator RF BPF (750~860MHz) Analog Rx Digital Rx λ 3 1.2dBm λ 4-20dBm DWDM DEMUX OC-48 Error Detector Digital Rx Digital Rx Digital Rx λ 5-20dBm λ 6-20dBm λ 7-20dBm
Bi-Directional Hybrid DWDM System 3dBm 20dBm 20dBm 3dBm MATRIX SX-16 2 3... λ 1 =1554.1nm Externally Modulated Transmitter EDFA-Ι EDFA-ΙΙ λ 2 =1552.4nm Externally Modulated Transmitter 2 3... MATRIX SX-16 78 78 4.77dBm 4.77dBm λ 3 =1550.9nm λ 4 =1549.3nm OC-48 Pattern Gennrator OC-48 TX OC-48 TX OC-48 Pattern Gennrator 2.5Gb/s DWDM MUX/DEMU X 80km LEAF DWDM MUX/DEMU X 2.5Gb/s. CNR 2CSO HP-8591C 3CTB Analog Rx λ 2 λ 1 Analog Rx HP-8591C CNR 2CSO 3CTB 0dBm 0dBm OC-48 BER Error Digital Rx λ 4 Detector λ 3 Digital Rx OC-48 Error Detector BER -15.23dBm -15.23dBm
Self-Phase Modulation Nonlinear Medium Frequency Chirp Self-Phase Modulation ( SPM ) Spectral Broadening Z : Normalized Distance Normalized Intensity 1.0 0.8 0.6 0.4 0.2 0.0-3 Z=5 2 1 0-2 -1 0 1 2 3 Normalized Frequency
Impact of Raman Scattering in DWDM System Output Spectrum Input Spectrum Optical Fiber λ 1 λ 2 λ 3 λ 4 λ 5 λ 1 λ 2 λ 3 λ 4 λ 5 Channel 1 Input Channel 2 Channel 1 Output Channel 2
Impact of Cross-Phase Modulation in DWDM System XPM-Induced Power Fluctuation P Phase modulation increases with number of channels or the total power. Phase shift by XPM twice the amount of SPM. Generation of nonlinear chirp on signals each other, increasing for fast pulse transitions.
Impact of Four-Wave Mixing in DWDM System FWM-Induced Crosstalk N-Channel WDM System (i, j, k N) ω i j k = ω i + ω j - ω k ω i ω j ω k Optical Fiber ω i ω i j k ω j ω k
Principle of Dispersion Compensator 3dB coupler Chirped FBG
MATRIX SX-16 2 3. 78 λ 1 =1541.35nm -0.2dBm/λ 1, λ 2 13.9dBm/λ 1, λ 2 Externally 13.8dBm/λ 1, λ 2 1.4dBm/λ 1, λ 2 Modulated Transmitter... EDFA-Ι EDFA-ΙΙ MATRIX SX-16 2 3.. 78.. Externally Modulated Transmitter λ 2 =1553.74nm 2 1 Coupler VOA 20km SMF VOA 40km SMF OB PF CNR CSO CTB HP-8591C Optical Receiver 4.2dBm/λ 1, λ 2 13.9dBm/λ 1, λ 2 1.0dBm EDFA-ΙΙΙ CNR CSO CTB HP-8591C Optical Receiver OBPF 1 2 Splitter 40km SMF 1.6dBm/λ 1, λ 2
MATRIX SX-16 2 3. 78... λ 1 =1541.35nm Externally Modulated Transmitter -0.2dBm/λ 1, λ 2 CFG 13.9dBm/λ 1, λ 2 13.8dBm/λ 1, λ 2 1553.74nm 1.4dBm/λ 1, λ 2 1541.35nm EDFA-Ι EDFA-ΙΙ MATRIX SX-16 2 3.. 78.. Externally Modulated Transmitter 2 1 Coupler 20km SMF VOA OC 6.2dBm/λ 1, λ 2 10dBm/λ 1, λ 2 VOA λ 2 =1553.74nm 40km SMF OB PF CNR CSO CTB HP-8591C Optical Receiver 4.2dBm/λ 1, λ 2 13.9dBm/λ 1, λ 2 1.0dBm EDFA-ΙΙΙ CNR CSO CTB HP-8591C Optical Receiver OB PF 1 2 Splitter 40km SMF 1.6dBm/λ 1, λ 2
Discussions β 1 = 17 ps/km/nm 100 km = 1700 ps/nm β 2 = -1438 ps/nm β 1 +β 2 = 1700 ps/nm - 1438 ps/nm = 262 ps/nm
Conclusion Conclusion
Bandwidth Demand Cycle Services & Applications Infrastructure Internet Subscribers Bandwidth Growth of 100 to 200 Times Over Next Four Years Services & Applications Higher Connectivity Speeds
Fiber count Bandwidth Increase 10 Gbit/s and Higher DWDM Long-Haul Metro Market Growth WAN LAN Internet SAN Access SONET/SDH ATM Application Requirements IP Ethernet XDSL WAN = Wide Area Network LAN = Local Area Network SAN = Storage Area Network DWDM = Dense Wavelength Division Multiplexing SONET = Synchronous Optical NETwork SDH = Synchronous Digital Hierarchy ATM = Asynchronous Transfer Mode IP = Internet Protocol XDSL = X Digital Subscriber Line
World wide target Optical Cross-Connects, Interconnected Optical Rings OXC Technical Functionality Point-to-Point WDM WDM Rings, Programmable Add - Drop OADM Point-to-Point WDM with Fixed Add-Drop OADM OADM OADM STM-16 (2.5G) 16/32 λ OADM OADM OXC OADM OXC 4 ch. OXC OXC STM-16 (2.5G) 64 λ OXC System Metro Network Access Network STM-1/STM-4/STM-16 10M/100M/1G Ether 32 ch. FTTx Metro Ether EPON - Optical Add/Drop Multiplexer OXC - Optical Cross Connect 1996 2000 2003 2006 Time
Rainbow--- God Created Rainbow in Nature People Created DWDM in Future