Glossary

In reference to light, a wavelength shorter than 1000nm.

The standard international system of metric units.

The information conveyed through a communication system.

The process whereby a protocol at the Physical layer receives information from the upper layers and translates all the data into signals that can be transmitted on a transmission medium.

The ratio of received signal level to received noise level, expressed in decibels and abbreviated SNR or S/N. A higher SNR ratio indicates better channel performance. The relationship between the usable intended signal and the extraneous noise present. If the SNR limit is exceeded, the signal transmitted will be unusable.

The process of transmitting data across the medium. Types of signaling include digital and analog, baseband and broadband.

Glass made mostly of silicon dioxide used in conventional optical glass that is used commonly in optical fiber cables.

A General Electric trademark for a material made from silicon and oxygen. Can be in thermosetting elastomer or liquid form. The thermosetting elastomer form is noted for high heat resistance.

The silver-gray voice-grade patch cable used to connect a telephone to a wall jack such as that used by home telephones. Silver satin cables are unsuitable for use in LAN applications because they do not have twisted pairs, and this results in high levels of crosstalk and capacitance.

(1) A link that can only carry a signal in one direction. (2) A fiber-optic cable or cord carrying a single fiber. Simplex cordage is mainly used for patch cords and temporary installations.

A term sometimes used to describe a single-fiber cable.

Data transmission over a circuit capable of transmitting in only one direction.

Optical fibers capable of carrying light in only one polarization.

Optical fibers capable of carrying light in only one polarization.

A circuit board containing the components needed for a computer that performs a prescribed task. A singleboard computer is often the basis of a larger piece of equipment that contains it.