See directional coupler, T-coupler, tee coupler.

The person or organization that requests an evaluation [ITSEC].

A certificate that indicates the restrictions on those documents and transactions that an entity may authorize. [After X9.45]

Radiation emitted when the internal energy of a quantum mechanical system drops from an excited level to a lower level without regard to the simultaneous presence of similar radiation.
Note: Examples of spontaneous emission include radiation from an LED, and radiation from an injection laser below the lasing threshold.

1. (COMSEC) [The] interception, alteration, and retransmission of a cipher signal or data in such a way as to mislead the recipient. [NIS]
2. (AIS) [An] attempt to gain access to an AIS by posing as an authorized user. [NIS]
3. Unauthorized use of legitimate Identification and Authentication (I&A) data, however it was obtained, to mimic a subject different from… (Read More →)

The use of auxiliary storage as buffer storage to reduce processing delays when transferring data between peripheral equipment and the processors of a computer.
Note: The term is derived from the expression "simultaneous peripheral operation on line. "

Irregular scattered patches of relatively dense ionization that develop seasonally within the E region and that reflect and scatter frequencies up to 150 MHz.
Note 1: The sporadic E is a regular daytime occurrence over the equatorial regions and is common in the temperate latitudes in late spring, early summer and, to a lesser degree, in early winter.
Note 2:… (Read More →)

Synonym sporadic E.

In satellite communications systems, a narrow beam from a satellite station antenna that illuminates, with high irradiance, a limited area of the Earth by using beam (directive) antennas rather than Earth-coverage antennas.

The jamming of a specific channel or frequency. [JP 1-02]