| 摘要 |
Radio working lines are provided to correspond to optical lines and a single radio standby line is provided. An optical-line failure detecting unit monitors occurrence of failure in each of the optical line, and a radio-line failure detecting unit monitors the occurrence of failure in each of the radio working lines. When occurrence of failure in an optical line has been detected, a relief-rank management unit makes the rank for relief of the radio working line corresponding to this optical line lower than rank for relief of radio working lines corresponding to optical lines that have not failed. When a failure has occurred in two or more radio working lines, a line changeover controller transmits data, which is to be sent to a radio working line that failed, via the radio standby line. |
