Nortel Networks 10292FA, 10396EA manual See SMF

64Glossary

single-mode fiber

See SMF.

SMF

A mode is one of the various light waves that can be transmitted in an optical fiber. Each optical signal generates many different modes, but in single-mode fiber the aim is to only have one of them transmitted. This is achieved through having a core of a very small diameter (usually around 10 micrometers), with a cladding that is usually ten times the core diameter. These fibers have a potential bandwidth of 50 to 100 GHz per kilometer.

Tx

transmit

A device that includes a LED or laser source and signal conditioning electronics that is used to inject a signal into optical fiber.

U

(vertical) unit

One U is 1.75 inches. Standard equipment racks have bolt holes spaced evenly on the mounting rails to permit equipment that is sized in multiples of this vertical unit to be mounted in the same rack.

WAN

wide area network

A physical or logical network that provides data communications to a larger number of independent users than are usually served by a LAN and is usually spread over a larger geographic area than that of a LAN.

wavelength

All electromagnetic radiation (radio waves, microwaves, ultraviolet light, visible light, etc.) is transmitted in waves, and the wavelength is the distance between the successive crests of the waves. In optical networks, you can think of different wavelengths as being different colors of light. Wavelengths of light are measured in nanometers or microns.

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