Glossary

The distance time over which a light form may be considered coherent. Influenced by a number of factors, including medium, interfaces, and launch condition. Time, all things being equal, is calculated by the coherence length divided by the phase velocity of light in the medium.

Where the light from a laser oscillator is mixed with the received signal, and the difference frequency is detected and amplified.

Light in which photons have a fixed or predictable relationship; that is, all parameters are predictable and correlated at any point in time or space, particularly over an area in a lane perpendicular to the direction of propagation or over time at a particular point in space. Coherent light is typically emitted from lasers.

The network error condition that occurs when electrical signals from two or more devices sharing a common data transfer medium crash into one another. This commonly happens on Ethernet-type systems.

Generic term for a sub band diplexor / triplexor. Example an MRC or a UCU.

Jumper connecting onto a Combiner towards the main feeder cable.

A commitment from your service provider stating the minimum bandwidth you will get on a frame relay network averaged over time.

A transmission scheme where voltages appear equal in magnitude and phase across a conductor pair with respect to ground. May also be referred to as longitudinal mode.

More commonly known as cable TV, a broadband transmission facility that generally uses a 75 ohm coaxial cable to carry numerous frequency-divided TV channels simultaneously. CATV carries high-speed Internet service in many parts of the world.

A wiring device that meets all characteristics of a standard is said to be in compliance with that standard. For example, a data jack that meets all of the physical, electrical, and transmission standards for ANSI/TIA/EIA- 568-B Category 5e is compliant with that standard.

A cable that typically has at least two different types of transmitting media inside the same jacket; for example, UTP and fiber.

The process of joining several fibers together end to end.

The coefficient used to scale bandwidth when several fibers are joined together.

A multiport repeater or hub.