Digital communicating method and device

PURPOSE: To attain communication for relay with high reliability by forming a serial bit flow constituted of continuous frames including the constant number of bits from each channel. CONSTITUTION: A relay closed signal, data signal, and digitized voice signal are turned into a serial bit flow constituted of the constant number of bits, for example, continuous frames obtained by time-division multiplexing one byte data by a multiplexer/demultiplexer 3. This serial bit flow is tramsitted from an optical transmitter 5 through a fiber optic cable 9 to an optical receiver 11, and multiply separated into the relay closed signal, data signal, and digitized voice signal by the multiplexer/demultiplexer 3. COPYRIGHT: (C)1989,JPO