This publication is directed towards all who deal with design, construction and maintenance of fiber optic cable plants. Furthermore, it provides basic information as an introduction to specialized technical literature. In order to make it easier to study the many specialized publications, the book contains a detailed glossary of technical terms. For this edition, the section on optical nonlinear effects has been enlarged and information on nonzero dispersion shifted fibers has been added. The chapter "fiber optic modules and components" has been rewritten and considerably enlarged.