Link level

Link level: In the hierarchical structure of a primary or secondary station, the conceptual level of control or data processing logic that controls the data link.

Note: Link-level functions provide an interface between the station high-level logic and the data link. Link-level functions include (a) transmit bit injection and receive bit extraction, (b) address and control field[?] interpretation, (c) command response generation, transmission and interpretation, and (d) frame check sequence computation and interpretation.

Source: from Federal Standard 1037C