Dwdm12
- 2. Dense Some times called stacked SDH/SONET Wavelength Division Multiplexing DWDM
- 3. …What is DWDM ? A multi channel fiber optic transmission system in which one fiber transmits No of client signals provided by different Wavelength optical carriers
- 4. Why DWDM ? a) Overcome fiber exhaust / lack of fiber availability problems (Better utilization of available fiber) d) Cost effective transmission e) No O-E-O conversion delays f) Wave length leasing instead of Bandwidth leasing b) Space & Power savings at intermediate stations c) Easier capacity expansion
- 5. …Why DWDM ? LTE LTE LTE LTE LTE LTE LTE LTE Traditional Network with Repeaters, no WDM 75% fewer fibersWDM Network with Repeaters LTE LTE LTE LTE LTE LTE LTE LTE 75% less equipmentWDM Network with Optical Amplifiers LTE LTE LTE LTE LTE LTE LTE LTE
- 6. Any Disadvantages of this Technology ? Yes of course… a) Multi channel failure due to line failure b) Requirements for more deliberate design of Dispersion management, gain profile management & launched power due to broader Wavelength range to be handled
- 7. WDM Classification: WDM Classification is based on the Channel spacing between 2 Wave lengths Channel spacing > 200GHz is called CWDM Channel spacing > 100 GHz is called WDM Channel spacing < 100GHz is called DWDM 100 GHz is equal to 0.8 nm
- 8. Infrared Spectrum O-Band E-Band S-Band C-Band L-Band 1260-1360nm 1460-1530nm 1530-1565nm CWDM CWDM Future DWDM DWDM DWDM
- 9. Low-loss range 0.1 0.2 0.3 0.0 1300 1400 1500 1600 Wavelength (nm) L O S S db/km C-Band L-Band
- 10. (nm) 1532.68 1533.47 1534.25 1535.04 1535.82 1536.61 1537.40 1538.19 1538.98 1539.77 1540.56 1541.35 1542.14 1542.94 1543.73 1544.53 1545.32 1546.12 1546.92 1547.72 1548.52 1549.32 1550.12 1550.92 1551.72 1552.52 1553.33 1554.13 1554.94 1555.75 1556.56 1557.36 1558.17 1558.98 1559.79 1560.61 1561.42 1562.23 1530.33 1531.12 1531.90 (THz) 195.7 195.6 195.5 195.4 195.3 195.2 195.1 195.0 194.9 194.8 194.7 194.6 194.5 194.3 194.2 194.1 194.0 193.9 193.8 193.7 193.6 193.5 193.4 193.3 193.2 193.1 193.0 192.9 192.8 192.7 192.6 192.5 192.4 192.3 192.2 192.1 192.0 191.9 196.0 195.9 195.8 C37 C36 C35 C34 C33 C32 C31 C30 C29 C28 C27 C26 C25 C24 C23 C22 C21 Tonech. C20 C19 C18 C17 C16 C15 C14 C13 C12 C11 C10 C09 C08 C07 C06 C05 C04 C03 C02 C01 C40 C39 C38 Carrier wavelength Carrier frequency Channel number Note 1: Optical carriers are allocated on ITU-T 100 GHz (0.1 THz) grid in Rec. G. 692. 2: Tone channel is dedicated for operation & maintenance support. Wavelength allocation in C-Band
- 11. Main Components in DWDM 1) Transponder 2) Omux/Odmux 3) Optical Amplifier 4) OADM 5) Regenerator
- 12. Client signals Client signalsWDM aggregate signals IL-AMP span IL-AMP #1 IL-AMP #n IL-AMP #1 IL-AMP #n TERM system TERM system Intermediate regenerator (n-1) IL-AMP spans Wavelengthconversion Opticalmux/demux Wavelengthconversion Opticalmux/demux Opticalmux/demux Ch-signalregeneration Line system …DWDM Components
- 13. Transponder A device that takes an optical signal, performs electrical 3R regeneration & re-transmits the signal in optical form In to Wavelength grid as per G.192 It allows any Wavelength as input to DWDM For every input Wavelength, one transponder is required Its very useful for Wavelength leasing, as customer can Send any wavelength
- 14. Omux/Odmux Various Transponder outputs (Wavelengths) will be provided as Inputs to Mux. Each input is equipped with A selective filter of certain Wavelength. The output of these filters are coupled to a Single Mode fiber At the Receiver end, these Wavelengths are separated again by a Demux & directs them to individual Transponders Both Mux & Demux are identical components, only difference is that they are driven in opposite direction
- 15. OMUX
- 16. Transmit Amplifier (TXA) OMUX Aggregate Signal over n-channels with wavelengths ranging from λ1 to λn. Channel spacing is 100 GHz and even. Channel #1 #2 #3 #(n-1) #(n-2) #n Wavelength λ1 λ2 λ3 λ(n-1) λ(n-2) λn λ1 λ2 λnλ(n-1) 100 GHz ClientOMUX
- 17. Optical Amplifier Where do we require Optical Amps ? a) Booster/Post Amp Boosts the signal at Transmitter end to compensate relatively low output power of laser transmitters b) Line Amp Used at regular intervals to compensate fiber transmission loss c) Pre Amp Boosts signal prior to Optical detectors to increase the Rx sensitivity
- 18. …Optical Amplifier Tx Rx PreamplifierTx Rx Line amplifier Tx Rx Booster/Post Amplifier
- 19. OADM Hence A special type of Mux is designed called Optical Add/Drop Mux With an Add/drop facility, new channels can be added to & others can be dropped off the transmission link In general, not all transmission channels have the same start & destination This Add/Drop function is completely in Optical form
- 20. …OADM
- 21. Regenerator Regenerator is nothing but an Amplifier, with addition of 3R function Since noise level also amplifies along with original signal in an ordinary amplifier, it requires to supress this noise at intermediate stations Regeneration requires at every 600kms distance
- 23. What is 3R generation ? Re-amplification – 1R Re-shaping – 2R Correcting noise & dispersion Remove noise from a digital signal & shape it in to clear 1’s & 0’s Boost up the received weak signals to transmit further It is done by Optical Amps Done by DCF & OEO
- 24. Re-timing – 3R Synchronizing with Network clock Adjusting the precise location of 1’s & 0’s in a detected signal in order to match them to the bit rate of system By using PLL & optical clock recovery
- 26. 1626 LM • Up to 96 channels at 10 Gb/s in extended C band with 50 GHz spacing • 1686 WM and 1640 WM upgrade • Line optical fibre amplifiers • 4x2.5 Gb/s concentrator (TRBC) • Enhanced FEC • Point-to-point and ring configurations • Bi-directional G709 10 Gb/s transponders • Tunable laser over 2 channels and the whole C-Band • Q3 and TL1 management interfaces • 1+N Optical channel protection with external OCP • Optical supervisory channel • Performance Monitoring
- 27. 1696 MS 32+32 bidir channels in one rack 8ch.+8ch.+8ch.+8ch. modular HUB node 1ch., 2ch., 4ch. and 8ch. low loss OADM Low cost optical amplifiers New 4Any concentrator (4xANY_P) CPE mechanical Point-to-point and ring configurations Multi-rate and 10Gb/s transponders Tunable laser over 2 channels Q3 and TL1 management interfaces 1+1 Optical channel protection (O-SNCP) Optical supervisory channel Performance Monitoring
- 28. DWDM • 1640WM : a core DWDM system supporting up to 160 channels (upgradeable up to 240 channels) and working at different standard synchronous bit- rates from 2.5Gb/s to 40Gb/s. • 1686WM : a regional and metropolitan DWDM system – scalable up to 32 channels – supporting different bit-rates from 100Mb/s to 10Gb/s.