CHANGEOVER CONTROL SYSTEM FOR STANDBY LINE OF ARBITRARY TYPE BY INFORMATION TRANSMISSION DENSITY AUTOMATIC MANAGEMENT

摘要

PURPOSE:To increase the relieve rate against a simultaneous fault or the like by not multiplexing an idle data before multiplexing as an invalid data but sending only a valid data. CONSTITUTION:A multiplexer 49 selects a non-idle data among plural data sent to a digital transmission line and multiplexes the selected data, a demultiplex distributer 50 demultiplexes the sent data to demultiplexes the data based on a data identification signal provided to each data and a line changeover device 5 recognizes digital transmission lines not idle to be standby lines and relieves a faulty non-idle transmission line by using a standby line. Thus, when plural non-busy transmission lines exist, it is equivalent that plural standby lines are provided and when plural current lines are faulty simultaneously, they are relieved simultaneously.