Ing.Comunicaciones Y Electronica

Contents
Section 1 DWDM Overview | 1-1 |
1.1 DWDM Technology Background | 1-1 |
1.2 DWDM Principles Overview | 1-2 |
1.3 DWDM Equipment Operating Modes | 1-3 |
1.3.1 Two-fiber bi-directional transmission | 1-3 |
1.3.2 Single fiber bi-directional transmission | 1-4 |
1.3.3 Add and drop of optical signals | 1-5 |
1.4 Application Modes of DWDM | 1-5 |
1.5 Advantages ofDWDM | 1-5 |
Section 2 DWDM Transmission Media | 2-1 |
2.1 Optical Fiber Structures | 2-1 |
2.2 Types of Optical Fiber | 2-2 |
2.3 Basic Features of Optical Fiber | 2-3 |
2.3.1 Physical Dimension (Mode field diameter) | 2-3 |
2.3.2 Mode Field Concentricity Error | 2-4 |
2.3.3 Bend Loss | 2-4 |
2.3.4 Attenuation Constant | 2-4 |
2.3.5 Dispersion Coefficient | 2-5 |
2.3.6Cutoff Wavelength | 2-6 |
2.4 Types and Properties of Optical Fiber Cable | 2-6 |
2.4.1 Types of Optical Fiber Cable | 2-6 |
2.4.2 Properties of Optical Fiber Cable | 2-6 |
Section 3 DWDM Key Technologies | 3-1 |
3.1 Lasers | 3-1 |
3.1.1 Laser Modulation Modes | 3-1 |
3.1.2 Wavelength Stability and Control of Laser | 3-4 |
3.2 Erbium-doped Optical Fiber Amplifier (EDFA) |3-5 |
3.2.1 EDFA Operating Principle | 3-5 |
3.2.2 Applications of EDFA | 3-7 |
3.2.3 Gain Control of EDFA | 3-9 |
3.2.4 Limitations of EDFA | 3-13 |
3.3 DWDM Components | 3-14 |
3.3.1 Optical Grating Type DWDM Component | 3-15 |
3.3.2 Dielectric Film Type DWDM Component | 3-16 |
3.3.3 Fused Conical Type DWDM Component | 3-17 |
3.3.4 Integrated Optical Waveguide TypeDWDM Component | 3-17 |
3.3.5 Performances of DWDM Components | 3-18 |
Section 4 DWDM Networking Design | 4-1 |
4.1 Some Network Element Types of DWDM | 4-1 |
4.1.1 Optical Terminal Equipment (OTM) | 4-1 |
4.1.2 Optical Line Amplification Unit (OLA) | 4-2 |
4.1.3 Optical Add/drop Multiplexing Unit (OADM) | 4-3 |
4.1.4 Electrical Regeneration Unit (REG) | 4-4 |
4.2 GeneralConstitution of DWDM network | 4-5 |
4.2.1 Point-to-point Networking | 4-5 |
4.2.2 Chain Type Networking | 4-6 |
4.2.3 Ring Type Networking | 4-6 |
4.2.4 Network Management Information Channel Backup and Interconnection Capability | 4-7 |
4.3 Factors To Be Considered in DWDM Networking | 4-9 |
4.3.1 Dispersion Limited Distance | 4-9 |
4.3.2 Power | 4-10 |
4.3.3 OpticalSignal-to-Noise Ratio | 4-11 |
4.3.4 Other Factors | 4-14 |
4.4 DWDM Network Protection | 4-23 |
4.4.1 Protection Based on single Wavelength | 4-23 |
4.4.2 Optical Multiplex Section (OMSP) Protection | 4-25 |
4.4.3 Applications in Ring Networks | 4-26 |
4.5 Analysis to The Examples | 4-27 |
4.5.1 Networking Diagram (Physical Network Stations) | 4-27 |
4.5.2 Networking Diagram(considering the dispersion limited distance of the lasers to divide the regenerator sections of the network) | 4-27 |
4.5.3 Networking Diagram (considering the power of optical amplifiers to divide the optical regenerator sections) | 4-28 |
4.5.4 Networking Diagram (considering OSNR) | 4-29 |

Section 1 DWDM Overview

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 Objectives:-------------------------------------------------
To master the concepts of DWDM.
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To know the background and technology characteristics of DWDM.

1.1 DWDM Technology Background
With the dramatic increase of voice services and emergence of various new services, especially the quick change of IP technology, network capacity will inevitably befaced with critical challenge. Traditional methods for transmission network capacity expansion adopt space division multiplexing (SDM) or time division multiplexing (TDM).
1. Space Division Multiplexing (SDM)
Space division multiplexing linearly expands the transmission capacity by adding fibers, and the transmission equipment is also linearly added.
At present, fiber manufacture technology is...