1. Bandwidth = Indicates the transmission capacity of media. For copper cables, bandwidth is deﬁned using signal frequency and speciﬁed in hertz (Hz). For optical ﬁber, wavelength in nanometers (nm) deﬁnes bandwidth. Also refers to the amount of data that can be sent through a given channel and is measured in bits per second.
2. Attenuation = A general term indicating a decrease in power (loss of signal) from one point to another. This loss can be a loss of electrical signal or light strength. In optical ﬁbers, it is measured in decibels per kilometer (dB/km) at a speciﬁed wavelength. The loss is measured as a ratio of input power to output power. Attenuation is caused by poor-quality connections, defects in the cable, and loss due to heat. The lower the attenuation value, the better. Attenuation is the opposite of gain. See Chapter 1 for additional information on attenuation and the use of decibels.
3. Application = (1) A program running on a computer. (2) A system, the transmission method of which is supported by telecom-munications cabling, such as 100Base-TX Ethernet, or digital voice.
4. dark ﬁber = An unused ﬁber; a ﬁber carrying no light. Common when extra ﬁber capacity is installed.
5. Riser = (1) A designation for a type of cable run between ﬂoors Fire-code rating for indoor cable that is certiﬁed to pass through the vertical shaft from ﬂoor to ﬂoor. (2) A space for indoor cables that allow cables to pass between ﬂoors, normally a vertical shaft or space.
6. Ripcord = A length of string built into optical ﬁber cables that is pulled to split the outer jacket of the cable without using a blade.
7. Core = The central part of a single optical ﬁber in which the light signal is transmitted. Common core sizes are 8.3 microns, 50 microns, and 62.5 microns. The core is sur-rounded by a cladding that has a higher refractive index that keeps the light inside the core. The core is typically made of glass or plastic.
8. Crosstalk = The coupling or transfer of...