A basic principle of optics, that no passive optical system can increase the quantity L/n2, where L is the radiance of a beam and n is the local refractive index.
Note: "Conservation of radiance" was formerly called "conservation of brightness" or the "brightness theorem. "

A carrier authorized to provide telecommunications services both within and outside World Zone 1 using the yyNorth American Numbering Plan (NANP)and the international dialing plan, respectively. [T1.104-1988]

Local communications service provided by GSA to all Federal agencies located in a building, complex, or geographical area.

In video, an image coding system that derives a luminance signal and two bandwidth-limited color-difference signals, to provide luminance information that is encoded into one signal supplemented by, but totally independent of, two color signals carrying only chrominance information, i.e., hue and saturation.
Note 1: Constant luminance is only achieved when the luminance and chrominance vectors are derived from linear… (Read More →)

The process of creating a Target of Evaluation [ITSEC].

A service feature that allows a speaker on an extension instrument to place one call on hold and to speak with another caller on a separate line.

A term used to denote either an IPTV Subscriber or an IPTV User (see also IPTV Consumer).

The domain where the IPTV services are consumed. In the consumer domain, a single terminal may be used for service consumption, but also a network of terminals and related devices may be present for this purpose. The domain may also be a mobile end device in this case the delivery system of a network provider is a wireless Wide Area… (Read More →)

A device within the Consumer Domain such as an ITF or a DNG.

1. The introduction of data of one security [classification or] security category into data of a lower security classification or different security category. [2382-pt.8] [INFOSEC-99].
2. Relative to numbering guidelines and FCC regulations, contamination occurs when at least one telephone number within a thousands-block of telephone numbers is not available for assignment to end users or customers. Blocks contaminated up… (Read More →)