A synchronous communications protocol requiring only a single bit to communicate a command signal to the target station. Bit-oriented protocols transmit information without regard to character boundaries and thus handle all types of information images. Bit-oriented protocols are much less overhead-intensive, as compared to byte-oriented protocols, also known as character-oriented protocols. Bit-oriented protocols are usually full-duplex (FDX) and operate over dedicated, four-wire circuits. Examples include Synchronous Data Link Control (SDLC) and the High-Level Data Link Control (HDLC). See also bit, byte-oriented protocol, FDX, four-wire circuit, HDLC, protocol, SDLC, and synchronous.