Optical technology involves research into components, such as couplers, amplifiers, switches, etc., that form the building blocks of the networks. Some of the main components used in optical networking are described in Appendix A1. With the help of these components, one designs a network and operates it. Issues in network design include minimizing the total network cost, the ability of the network to tolerate failures, the scalability of the network to meet future demands based on projected traffic volumes, etc. The operational part of the network involves monitoring the network for proper functionality, routing traffic, handling dynamic traffic in the network, reconfiguring the network in the case of failure, etc. In this chapter, these issues are introduced in brief, followed by a discussion of the two main issues in network operation, namely survivability and how traffic grooming relates to managing smaller traffic streams.

Network design

Network design involves assigning sufficient resources in the network to meet the projected traffic demand. Typically, network design problems consider a static traffic matrix and aim to design a network that is optimized based on certain performance metrics. Network design problems employing a static traffic matrix are typically formulated as optimization problems. If the traffic pattern in the network is dynamic, i.e. the specific traffic is not known a priori, the design problem involves assigning resources based on certain projected traffic distributions. In the case of dynamic traffic the network designer attempts to quantify certain network performance metrics based on the distribution of the traffic. The most commonly used metric in evaluating a network under dynamic traffic patterns is the blocking probability.