Equipment Room.
A centralized space for telecommunications equipment that serves the occupants of the building.
Equipment housed herein is considered distinct from a telecommunications closet because of its nature or complexity of
the equipment.
Frequency.
Of a periodic wave, the number of identical cycles per second. Usually expressed in Hertz.
Fresnel Reflection.
The reflection that occurs at the planar junction of two materials having different refractive indices;
Fresnel reflection is not a function of the angle of incidence.
Graded-index Fiber.
An optical fiber whose core has a nonuniform index of refraction. The core is composed of
concentric rings of glass whose refractive indices decrease from the center axis. The purpose is to reduce modal dispersion
and thereby increase fiber bandwidth.
Horizontal Cross-Connect (HC).
A cross-connect of horizontal cabling to other cabling, e.g., horizontal, backbone,
equipment.
Index of Refraction.
The ration of the velocity of light in free space to the velocity of light in a given material.
Insertion Loss.
The loss of power that results from inserting a component, such as a connector or splice, into a previously
continuous path.
Interconnection.
A connection scheme that provides for the direct connection of a cable to another cable or to an
equipment cable without a patch cord or jumper.
Intermediate Cross-Connect (IC).
A cross-connect between the main cross-connect and the horizontal cross-connect in
backbone cabling.
Laser.
Light Amplification by Stimulated Emission of Radiation. A light source producing, through stimulated emission,
coherent, near monochromatic light. Lasers in fiber optics are usually solid-state semiconductor types.
Light-Emitting Diode (LED).
A semiconductor diode that spontaneously emits light from the PN junction when forward
current is applied.
Main Cross-Connect (MC).
The cross-connect in the main equipment room for connecting entrance cables, backbone
cables, and equipment cables.
Material Dispersion.
Dispersion resulting from the different velocities of each wavelength in an optical fiber.
Modal Dispersion.
Dispersion resulting from the different transit lengths of different propagating modes in a multimode
optical fiber.
Mode.
A possible path followed by light rays.
Appendix C - Glossary, cont.
4-4
UNIT 3
APPENDICES
APPENDICES
UNIT 4