2. --PRESENTED BY DEEPAK KUMAR VERMA DEPT - ECE SEM - 6 TH ROLL - 09119003076 UNDER THE GUIDENCE OF…. Mr. SUDIP KUMAR GHOSH (Asst.Prof.Dept. of ECE)

3. WDM is a technology which multiplexes multiple optical carrier signals on a single optical fiber by using different wavelengths of laser light to carry different signals. T here are two types of WDM— > C oarse WDM > D ense WDM 3

4. F rom both technical and economic perspectives, the ability to provide potentially unlimited transmission capacity is the most obvious advantage of DWDM technology. 4

5. > D ense wavelength division multiplexing (DWDM) is a technology that uses more than eight multiplexed signals to transmit many wavelengths of light simultaneously over a single optical fiber. 5

6. Late 1990’s Mid 1990’s Early 1990’s 1980’s 64 to 160 channels in 1550 nm window Next generation DWDM system Channel spacing of 0.2 to 0.4 nm 16 to 40 channels in 1550 nm window DWDM (Dense wdm) Channel spacing of 0.8 to 1.6 2 to 8 channels in 1550 nm window Passive (or) 2 nd generation WDM Channel spacing of~ 3.2 nm 2 channels WWDM (Wideband WDM) 1310 nm & 1550 nm 6

7. *A basic DWDM system contains several main components: (a) Transmitter (transmit transponder) (b) Multiplexer/ demultiplexer (c) Amplifier (d) Optical fiber (media) (e) Receiver (receive transponder) 7

8. 8

9. o Multiplexing and Demultiplexing in a Unidirectional System o Multiplexing and Demultiplexing in a Bidirectional System 9

10.  Prism Refraction.  Waveguide Grating Diffraction.  Arrayed Waveguide Grating.  Multilayer Interference Filters. 10

11. INTERFACES OF DWDM:: By using DWDM as a transport for TDM, existing SONET equipment investments can be preserved. Often new implementations can eliminate layers of equipment. SONET TERMINAL ATM SWITCH LAYER -3 SWITCH WDM OC-n OC-48C FIBER 11

12. Attenuation—decay of signal strength, or loss of light power, as the signal propagates through the fibre. Chromatic dispersion—spreading of light pulses as they travel down the fibre. Nonlinearities—cumulative effects from the interaction of light with the material through which it travels, resulting in changes in the lightwave and interactions between lightwaves. 12

13. The requirements in the metropolitan market may differ in some respects from those in the long-haul network market. > Some key requirements for DWDM systems in the MAN include the following---- Multiprotocol support Scalability Reliability and availability Openness (interfaces, network management, standard fibre types,electromagnetic compatibility) Ease of installation and management Size and power consumption Cost effectiveness 13

14. It was first deployed on long-haul routes in a time of fiber scarcity. Then the equipment savings made it the solution of choice for new long-haul routes, even when ample fiber was available. Alternatives for capacity enhancement exist, such as pulling new cable and SONET overlays, but DWDM can do more. 14

15.  Increases bandwidth (speed and distance).  Does not require replacement or upgrade their existing legacy systems.  Provides "next generation" technologies to meet growing data needs.  Less costly in the long run because increased fiber capacity is automatically available; don't have to upgrade all the time 15

16. DWDM promises to solve the "fiber exhaust" problem and is expected to be the central technology in the all- optical networks of the future. This increase means that the incoming optical signals are assigned to specific wavelengths within a designated frequency band, then multiplexed onto one fiber. This process allows for multiple video, audio, and data channels to be transmitted over one fiber while maintaining system performance and enhancing transport systems. This technology responds to the growing need for efficient and capable data transmission by working with different formats, such as SONET/SDH, while increasing bandwidth. 16