Communications equipment at either end of a communications link, used to permit the stations involved to accomplish the mission for which the link was established. 2. In radio-relay systems, equipment used at points where data are inserted or derived, as distinct from equipment used only to relay a reconstituted signal. 3. Telephone and telegraph switchboards and other centrally located equipment at which communications circuits are terminated. 4. Equipment that originates or terminates signals at the specified rate.