OTN Principles and Equipment Introduction

WDM Principle
Wavelength Division Multiplexing: Multiplexing optical signals of different wavelengths into the same optical fiber for transmission, this method is called wavelength division multiplexing (WDM). Features: Multi-wavelength multiplexing/high-speed long-distance transmission/optical layer monitoring and management.

Coarse wavelength division multiplexing (CWDM): The wavelength interval is 20nm. With the development of technology, more and more optical signals can be multiplexed, and dense wavelength division multiplexing technology has emerged.

Dense wavelength-division multiplexing (DWDM): Wavelength interval is less than 0.8nm.

OTN — Optical Transport Network
Optical Transport Network (OTN) is defined by recommendation G.709, provides a network-wide framework that adds SONET/SDH-like features to WDM equipment (also known as Wavelength Switched Optical Network equipment, or WSON equipment). It creates a transparent, hierarchical network designed for use on both WDM/WSON devices and TDM devices. It provides an efficient way to transport, switch, and multiplex different services onto high-capacity wavelengths across the optical network.

Features
- WDM technology is adopted on the line
- Multiple client signal encapsulation and transparent transmission
- Large-grained bandwidth multiplexing, crossover, and configuration
- Strong overhead and maintenance management capabilities
- Enhanced networking and protection capabilities

Differences and Relevance Between WDM and OTN

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