| 摘要 |
PURPOSE:To cope with a fault such as line blocking if a line fault takes place by converting a digital primary group signal and a basic supergroup signal and sending either of two group pilots as an alarm signal. CONSTITUTION:Supergroup transmultiplexers 23, 24 apply mutual transformation between digital primary groups 11 to 15 and two basic supergroup signals. That is, since one digital primary group corresponds to two group band signals, one of the two group pilots is used as an alarm signal. Thus, when the supergroup transmultiplexer 23 detects an alarm to an opposite station from the digital primary group 201, the alarm is sent by stopping the transmission of one of the two group pilots and the supergroup transmultiplexer 24 judges it that the two group multiplexers 23 give an alarm to send the alarm to opposite station by the digital primary group. |
