| 摘要 |
PURPOSE:To attain alarm transfer of a digital transmission line via a frequency division multiplex system line for a group band by using a transmultiplexer sending an opposite station alarm and a host station alarm through an analog transmission line. CONSTITUTION:When a transmultiplexer 23 detects an opposite station alarm from a digital primary group transmission line 201, the transmission of a group pilot defined as an alarm to a frequency division multiplex(FDM) transmission line 205 is stopped. Thus, a transmultiplexer 24 recognizes it that the transmultiplexer 23 sends an opposite station alarm, and sends an opposite station alarm to a digital primary group transmission line 203. When the transmultiplexer 23 detects a host station alarm from the digital primary group transmission line 201, the transmission of the group pilot defined as monitor is stopped. Thus, the transmultiplexer 24 recognizes it that the transmultiplexer 23 sends the host station alarm and sends the host station alarm to the digital primary group transmission line 203. Thus, when a transmission line 205 is interrupted due to a fault, since the two group pilots are interrupted simultaneously, the transmultiplexer 24 recognizes it as input signal interruption. |
