1 / 35

INTRODUCTION TO DWDM

This article provides an introduction to dense wavelength division multiplexing (DWDM) technology, including its need, challenges, and advantages. It discusses the components and workings of DWDM systems, as well as the benefits it brings to operators. The article also explores the economic and operational advantages of DWDM and its evolution over time. Written in English.

aglenn
Download Presentation

INTRODUCTION TO DWDM

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. INTRODUCTION TO DWDM ALTTC/TX-I/DWDM

  2. CONTENTS • The need for DWDDM • Fibre exhaust- alternatives • The challenge: • Tapping the unlimited fibre bandwidth • Achieving the networking functions in the optical domain • Wdm approach to fibre exhaust • Wdm functional block schematic • Differences from conventional system: the amplifier • Dwdm systems at present • Optical amplifiers • Dwdm components • Optical bands • Standard wavelengths: ITU grid • Dwdm applications : • Benefit to operators • New issues before planners ALTTC/TX-I/DWDM

  3. 2.5- Gbit/s 2.5-Gbit/s 2.5- Gbit/s 2.5 Gbit/s 2.5- Gbit/s 2.5 Gbit/s 2.5- Gbit/s reciever transmitter FIBRE EXHAUST 10-Gbit/s 10-Gbit/s 10-Gbit/s transmitter regenerator reciever INSTAL HIGHER BITRATE TDM EXPENSIVE, NEW FIBRE NEEDED ALTTC/TX-I/DWDM

  4. FIBRE EXHAUST 10-Gbit/s 10-Gbit/s 10-Gbit/s transmitter regenerator reciever 2.5- Gbit/s 2.5- Gbit/s 2.5-Gbit/s 2.5- Gbit/s 2.5 Gbit/s 2.5- Gbit/s 2.5 Gbit/s 2.5- Gbit/s 2.5- Gbit/s 2.5- Gbit/s 2.5- Gbit/s 2.5- Gbit/s DEMUX reciever reciever reciever reciever reciever transmitter MUX 2.5-Gbitt/s 2.5-Gbitt/s 2.5-Gbitt/s 2.5-Gbitt/s transmitter transmitter transmitter transmitter λ1 λ1 λ2 λ2 λ3 λ3 λ4 λ4 DEPLOY DWDM ALTTC/TX-I/DWDM

  5. 64-160 channels 25-50 GHZ spacing Late 1990’s 16-40 channels 100-200 GHz spacing Dense WDM, integrated systems with Network Management, add-drop functions. Mid 1990’s 2-8 channels passive WDM 200-400 GHz spacing WDM components/parts Early 1990’s Late 1980’s 2 channels Wideband WDM 1310 nm, 1550 nm EVOLUTION OF DWDM ALTTC/TX-I/DWDM

  6. THREE POSSIBLE SOLUTIONS • INSTAL NEW FIBRE • INVEST IN NEW TDM • TECHNOLOGIES TO • ACHIEVE HIGHER • BANDWIDTH. • DEPLOY DWDM EXPENSIVE VERY EXPENSIVE REQUIRE NEW TYPE FIBRE ECONOMICAL ACHIEVING HIGHER BANDWIDTH ALTTC/TX-I/DWDM

  7. THE CHALLENGE:Continuous growth in traffic… Calls for tapping the unutilized bandwidth of the media ACHIEVE NETWORKING FUNCTIONS (ROUTING etc) IN OPTICAL DOMAIN JUST LIKE WIDENING OF ROAD USING AVAILAB.E LAND TO MEET INCREASED TRAFFIC ALTTC/TX-I/DWDM

  8. DWDM BASICS DWDM MULTIPLEXER SINGLE FIBRE SDH OPTICAL SIGNALS NEW REQUIREMENTS: ALTTC/TX-I/DWDM

  9. Tx Rx OPTICAL SIGNALS. DEMUX MUX • 1 STM-1 STM-4 STM-16 ATM IP OFA • 2 . . . . W W D D M M • 16 TRANSPONDERS BLOCK SCHEMATIC ALTTC/TX-I/DWDM

  10. WDM MUX WDM DEMUX  1  OA OA 2  15  16   1-4 5-8 Wayside Optical Add/Drop Multiplexer TM TM ALTTC/TX-I/DWDM

  11. Optical Add/Drop Multiplexing l1 l1 Configurable OADM :1or2 l1 l2 l2 l2 l2 l1 l1 l2 l2 l2 l2 l1 Terminal Equipt In-Line Amplifier Terminal Equipt fixed OADM:2 OADM : Optical Add/Drop Multiplexer ALTTC/TX-I/DWDM

  12. OADM Connectivity • Omnibus 29 express ch 32 chWDM • From terminal to OADM, or from OADM to OADM ALTTC/TX-I/DWDM

  13. DIFFERENCES FROM OLD SYSTEM • REGs • FIBRES REQUIREMENT • LASERS • TYPES OF COMPONENTS • CAPACITY • FIBRE TRANSMISSION BEHAVIOUR ALTTC/TX-I/DWDM

  14. ADVANTAGES OF DWDM ALTTC/TX-I/DWDM

  15. Why Optical (DWDM) Networking? • Fibre Exhaust : Unlimited bandwidth on a fibre pair • Bit Rate Transparency • Format/Protocol Transparency : IP, ATM etc. • Efficient use and rearrangement of embedded optical capacity as per demand. • Minimal Capital Expenditure : Capacity Expansions Demand • Simpler Operations : Embedded DCC ALTTC/TX-I/DWDM

  16. Economics of WDM • Saving of regeneration costs: • one optical amplifier for many channels regeneration cost per channel drastically reduced • Saving of fibres/fibre shortage • Cost effective compared to laying new fibres ALTTC/TX-I/DWDM

  17. DWDM Components • Transmit • Receive • Repeater • Add Drop • Distribution: Cross connects ALTTC/TX-I/DWDM

  18. OPTICAL NETWORK ELEMENTS TP OA OADM OXC TP OMUX ODEMUX ALTTC/TX-I/DWDM

  19. OPTIONAL REGENERATOR Electrical REGENERATION O/E E/O TRANSPONDER / TRANSLATOR / WAVELENGTH CONVERTOR ALTTC/TX-I/DWDM

  20. Optical Multiplexers & Filters W\L FILTER W\L MULTIPLEXER W\L ROUTER ALTTC/TX-I/DWDM

  21. OPTICAL ADD DROP MUX M D COUPLER CIRCULATOR ALTTC/TX-I/DWDM

  22. OPTICAL CROSSCONNECT T SWITCH MATRIX T T T INPUT FIBRE LINKS OUTPUT FIBRE LINKS T T T T WAVELENGTH ADAPTATION TRIBUTARY LINKS ALTTC/TX-I/DWDM

  23. OPTICAL AMPLIFIERS Isolator Isolator Coupler Coupler Erbium-doped Fiber-(10-50 m) Pump laser Pump laser ALTTC/TX-I/DWDM

  24. NMS FOR DWDM SYSTEMS • NMS IN CONVENTIONAL SDH SYSTEMS: • DCC: TIME SLOTS • DWDM – NO TIME SLOTS • WAVELENGTH SLOTS • ONE WAVELENGTH IS DEDICATED FOR N.M.S. • OPTICAL SUPERVISORY CHANNEL • OSC needs to be accessed at all points in the network ALTTC/TX-I/DWDM

  25. Line Terminal Equipment In-line Amplifier Line Terminal Equipment Rx Tx 1 Rx Tx 2 1 1 Rx Tx 3 2 2 Rx Tx 4 DATA OUT DATA IN 3 3 Rx Tx 5 4 4 Rx Tx 6 5 5 Rx Tx 7 6 6 Rx Tx 8 7 7 Rx Tx OSC Tx sup Rx sup 8 8 System ControlProcessor System ControlProcessor Network Management Network Management Optical Supervisory Channel(OSC)  + supervisory ALTTC/TX-I/DWDM

  26. OPTICAL BANDS • EXTENSIVE USE OF WAVELENGTHS • DIFFERENT VENDORS:INTEROPERABILITY ISSUES • NEED FOR STANDARD WAVELENGTH VALUES • ITU Classification of bands • Standard values : ITU Grid • Center frequency: 193.10THz (1552.52 nm) • Standard spacing of 200, 100, 50 GHz for different applications ALTTC/TX-I/DWDM

  27. ITU-T BAND ALLOCATION C BAND L BAND Optical Supervisory channel RED BAND BLUE BAND 1500 1520 1530 1542 1547 1560 1620 • CBAND PRODUCTS ARE COMMERCIALLY AVAILABLE. • ERBIUM DOPED FIBRE AMPLIFIERS SUITABLE FOR • ‘C’ BAND. • GAIN IN RED BAND FLATTEST FOR EDFA. • SOME MANUFACTURERS PROVIDE 16 CHANNELS IN • RED BAND ONLY. OTHERS USE BOTH RED • & BLUE BANDS. ALTTC/TX-I/DWDM

  28. ITU –T G.692 Frequency Grid ALTTC/TX-I/DWDM

  29. LIMITATIONS • DWDM TRANSMISSION IS ANALOG. • THE IN LINE AMPLIFIERS ARE • ALSO ANALOG. • THIS IMPLIES THAT THE SIGNAL TO • NOISE RATIO WORSENS WITH • DISTANCE. • TO KEEP THE BER WITHIN LIMITS, • THE SIGNALS ARE REQUIRED TO BE • 3R PROCESSED IN ELECTRICAL • DOMAIN. • FIBRE DISPERSION IS ANOTHER • LIMITATION. ALTTC/TX-I/DWDM

  30. LIMITATIONS • THE MAXIMUM DISTANCE IS 640 Kms • MADE OF 8 SPANS OF 80 Kms. THE • ASSUMPTIONS ARE: • * FIBRE ATT INCLUDING SPLICE • LOSS IS 0.28 dB/km • * SPAN LOSS OF 22 dB. • * TOTAL DISPERSION IS LESS • THAN 12800 ps/nm. ALTTC/TX-I/DWDM

  31. New Applications with DWDM • Long Distance • Longer Regenerator spacing: Hundreds to Thousands of Kilometers • Saving of Regenerators • Very Low Bandwidth Cost • Scalability • Very Fast Commissioning of Optical Paths: Within a week as compared to several months/ year with old technologies • Advanced Networking Capabilities ALTTC/TX-I/DWDM

  32. New Applications with DWDM • Metropolitan Area Network • Unlimited Bandwidth, bit rate and format transparency • Efficient Bandwidth use and Management ALTTC/TX-I/DWDM

  33. New Applications with DWDM • High speed parallel Data Transport • Certain Computer Applications Require that Computer Centers be interconnected with multiple high speed channels that have capacity and availability requirements, as well as interlink delay restrictions that can not be met by TDM Transport Systems. • In General, DWDM Optical Transport Benefits all Delay Sensitive Applications ALTTC/TX-I/DWDM

  34. New Applications with DWDM • Wavelength Leasing • Network Customers are beginning to demand high capacity Network Transport that affords high reliability and security, as well as segmentations from the providers Network • A spare Wavelength (Leased ) is used to provide clear-channel transport to a customer • The Customer’s Bandwidth requirements are cleanly separated from the providers core Network Needs. ALTTC/TX-I/DWDM

  35. Thank You ALTTC/TX-I/DWDM

More Related