ing is rosy and that we should migrate all communications to a light-based system, we will also describe and discuss certain reasons why copper can remain a better choice than the use of optical fiber. Once we have an appreciation for the advantages and disadvantages associated with Chapter One the use of optical fiber, we will discuss a wide range of applications dependent on the use of light. We will conclude this introductory chapter with a preview of succeeding chapters. You can use this chapter preview by itself or in conjunction with the index to locate specific information of interest. While the chapters in this book were structured in a sequence to pro- vide an optimum benefit for readers, this author also recognizes the real- ity of a modern work environment where many persons receive assign- ments that require immediate access to information. To facilitate this fact of life, each chapter in this book was written as an entity to be as inde- pendent as possible from succeeding and preceding chapters. Thus, read- ers requiring access to specific information about a particular topic may be able to turn to the relevant chapter instead of reading all preceding chapters. However, an exception to this general rule might occur in instances where readers need background information concerning both the operation of a specific component of an optical transmission sys- tem and the use of an optical fiber transmission system within a partic- ular operational environment. In this situation, it will be necessary to read at least two chapters: one chapter describing the operation of a par- ticular optical transmission system component and the other chapter focusing on the operational environment for which the reader requires information. Now that we have an appreciation of where this chapter is headed, let's commence our reading effort by focusing on the advantages associ- ated with the use of optical transmission. Advantages of Optical Transmission When considering the use of an optical transmission system, most peo- p