Communications subsystem

In telecommunication, a communications subsystem is a functional unit or operational assembly that is smaller than the larger assembly under consideration.

Note: Examples of communications subsystems in the Defense Communications System (DCS) are (a) a satellite link with one Earth terminal in CONUS and one in Europe, (b) the interconnect facilities at each Earth terminal of the satellite link, and (c) an optical fiber cable with its driver and receiver in either of the interconnect facilities.

Source: from Federal Standard 1037C and from MIL-STD-188