Table of Contents:

Definition and Overview

1. The Evolving Core Optical Network

2. Economical Challenges

3. Two Types of Optical Switches

4. All-Optical Switches

5. Intelligent O-E-O Switches

6. Space and Power Savings

7. Optimized Optical Nodes

Self-Test

Glossary

PDF of this tutorial

A logical evolution path to the next-generation network must include the deployment of intelligent O-E-O switches to ensure that current needs are met as well as the addition of all-optical O-O-O switches when and where they make sense. Carriers are currently deploying intelligent O-E-O switches that offer space and power savings over traditional network architectures such as stacked SONET rings and digital cross-connects. These intelligent optical switches continue to benefit from technical advances and the cost reduction of electronic chip devices. They provide carriers the opportunity to implement new data-oriented services now and into the future. As all-optical switching technology matures, carriers need not worry about replacing their intelligent optical switches. Instead, carriers must optimize their network and service offering through the implementation of both switch types. A carrier whose primary service offering is bandwidth-based must maintain an intelligent O-E-O optical switch that is capable of multiplexing and demultiplexing the different traffic. Carriers, who have the infrastructure and operational processes to support wavelength-based services are candidates for early implementation of all-optical switches. Together the two switch types provide scalability, manageability, and flexibility without introducing new network-management challenges into the network.

Figure 10. O-E-O and O-O-O Optical Nodes

Most carrier services are currently bandwidth-based but will evolve to support more wavelength-based services, including optical virtual private networks and end-to-end wavelength services, where the end user has the power to change the bit rate at will. The increased rate of deployment of intelligent O-E-O switches is driving the emergence of next-generation optical networks. The addition of an all-optical O-O-O switch holds the promise of making this network even more flexible and manageable. Together the intelligent O-E-O switch and the all-optical O-O-O switch ensure a scalable next-generation network that can accommodate the dynamic nature of bandwidth-intensive broadband services.