tem: transmitter, receiver, and transmission medium. A laser or a light-emit- ting diode (LED) represents the transmitter, while a light detector, referred to as a photodetector or an optical detector, represents the receiver. Both are nor- mally solid-state semiconductor devices. As you might expect, the copper cable is replaced by an optical fiber as the transmission medium. Terminology In this book we will encounter both new and old terminology as well as some possibly confusing terminology that this section should help you understand. Concerning the latter, throughout this book this author uses the terms optical fiber and fiber optic interchangeably even though a purist might disagree. Thus, we will consider both glass and plastic to represent optical fibers as well as possible material used in a fiber optic. However, because plastic fiber provides only a fraction of the capability of glass fiber, we will specifically reference the former in this book. Otherwise, all references to fiber will be to glass-based fiber. Concerning other terminology, while we will review applicable termi- nology throughout this book, a reminder of prefix values might be in order, especially for a book that covers frequency, bandwidth, and wave- lengths that can considerably vary from the normal numbers that we work with on a daily basis. Thus, as a refresher, the prefix milli represents 10-3, micro represents 10-6, and nano represents 10-9, while kilo represents 10 3, mega represents 106, and giga represents 10°. Other prefixes worth not- ing with respect to the field of optical networking but rarely encoun- tered in everyday life are pico (10-12), femto (10-15), tera, a prefix that repre- sents a trillion (1012), and peta (1015), which represents a quadrillion. Deployment The deployment of optical networking devices is occurring at a rapid rate within the telephone company and cable television backbone Chapter One infrastructure into the local neighborhood and onto local area net- works (LANs). If you simply count the number of s