Loosely, the group of microwave frequencies from 4 GHz to 6 GHz used in satellite communications. 2. The band of satellite downlink frequencies between 3.7 and 4.2 GHz. Note 1: For federal procurement purposes, the radio frequency band(s) must be specified using the upper and lower limits of the band, per 47 CFR 300. Note 2: Letter designators of radio frequency bands are imprecise, and in the international community are deprecated and obsolete.

Abbreviation for communications-electronics.

A general-purpose, high-level, structured computer programming language. Note: C-language was originally designed for and implemented on the UNIX^TM operating system.

The term “C-Message Noise” denotes the frequency weighted average noise within an idle voice channel. The frequency weighting, called C-message, is used to simulate the frequency characteristic of the 5OO-type telephone set and the hearing of the average subscriber.

A noise spectral weighting used in a noise power measuring set to measure noise power on a line that is terminated by a 500-type set or similar instrument. Note: The instrument is calibrated in dBrnC.

The term “C-Notched Noise” denotes the C-message frequency weighted noise on a voice channel with a holding tone, which is removed at the measuring end through a notch (very narrow band) filter.

Abbreviation for central office.

Abbreviation for command and control warfare.

CA: Conditional Access

An assembly of one or more insulated conductors, or optical fibers, or a combination of both, within an enveloping jacket. Note 1: A cable is constructed so that the conductors or fibers may be used singly or in groups. Note 2: Certain types of communications cables, especially long submarine cables but also terrestrial cables, whether the communications media are metallic or optical fiber, may contain metallic conductors that supply power to repeaters (amplifiers). 2. A message sent by cable, or by any means of telegraphy (including wireless means).