Impairment Management and Survivability

This chapter discusses the causes of impairments in the optical network and how one takes them into account in the design, followed by the survivability issues in optical networks. It outlines the basic concepts of survivability and different protection and restoration schemes used in optical networks. Survivability can be provided in different layers in network: logical layers and optical layer. The fault‐management schemes in each layer have their own functionalities and characteristics. The chapter also discusses the survivability in the multilayer wavelength division multiplexing (WDM) optical networks. The protection techniques in the synchronous optical network and synchronous digital hierarchy networks are briefly described, which are still used in many of the current protocols in the WDM networks. It looks at protection functions in the optical layer and discusses how protection functions in the different layers of the network can work together.