Frequencies from 300 MHz to 3000 MHz. See electromagnetic spectrum.

Frequencies from 300 Hz to 3000 Hz. See electromagnetic spectrum.

The portion of the electromagnetic spectrum in which the longest wavelength is just below the visible spectrum, extending from approximately 4 nm to approximately 400 nm.
Note: Some authorities place the lower limit of uv at values between 1 and 40 nm, 1 nm being the upper wavelength limit of x-rays. The 400-nm limit is the lowest visible wavelength, i.e.,… (Read More →)

See UWB.

Unified Modeling Language

Universal Mobile Telecommunication System

Synonym illegal character.

A cell identified by a standardized virtual path identifier (VPI) and virtual channel identifier (VCI) value, which has been generated and does not carry information from an application using the ATM Layer service. [T1.627-1993]

Exposure of information to individuals not authorized to receive it. [INFOSEC-99]

A expression of the degree to which a system, subsystem, or equipment is not operable and not in a committable state at the start of a mission, when the mission is called for at an unknown, i.e., random, time.
Note 1: The conditions determining operability and committability must be specified.
Note 2: Expressed mathematically, unavailability is 1 minus the availability.… (Read More →)