Glossary

An optical fiber cable with dielectric strength elements that can span long distances between supports without the aid of other strength elements.

An electric current that cyclically reverses polarity.

A means of encoding information. ASCII is the method used by Microsoft to encode characters in text files in their operating systems.

Standard measuring gauge for nonferrous conductors (i.e., noniron and nonsteel). Gauge is a measure of the diameter of the conductor. The higher the AWG number, the smaller the diameter of the wire. See Chapter 1 for more information.

A unit of measure of electrical current.

Any device that intensifies a signal without distorting the shape of the wave. In fiber optics, a device used to increase the power of an optical signal.

The difference between high and low points of a wavelength cycle. The greater the amplitude, the stronger the signal.

A method of signal transmission in which the amplitude of the carrier is varied in accordance with the signal.With respect to optical fiber cabling, the modulation is done by varying the amplitude of a light wave, common in analog/RF applications.

A signal that varies continuously through time in response to an input. A mercury thermometer, which gives a variable range of temperature readings, is an example of an analogue instrument. Analogue electrical signals are measured in hertz (Hz). Analogue is the opposite of digital.

An electrical signal that varies continuously (is infinitely variable within a specified range) without having discrete values (as opposed to a digital signal).

A device used to convert analogue signals to digital signals for storage or transmission.

To determine whether a destination host is local or remote, a computer will perform a simple mathematical computation referred to as an AND operation.

With respect to fiber optics, the angle of a ray of light striking a surface or boundary as measured from a line drawn perpendicular to the surface. Also called incident angle.

With respect to fiber optics, the angle formed between the normal and a reflected beam. The angle of reflection equals the angle of incidence.

With respect to fiber optics, the angle formed between the normal (a line drawn perpendicular to the interface) and a refracted beam.