| 摘要 |
PURPOSE:To execute switching without cutting a call when a fault occurs in control CH by switching call CH for which a signal showing 'busy' is not transmitted to control CH when there is the call CH in plural call CH and waiting for call CH to become idle when all are busy and switching it to control CH. CONSTITUTION:The signal showing 'busy' is transmitted from plural call channels (CH) 2, 3,... to a control part 12 and a switching means 13 for non-call CH is provided for the control part 12. When there is the fault in control CH 1, the control part 12 switches call CH for which the signal showing 'busy' is not transmitted among plural call CH 2, 3, ... to control CH 1 by the switching means 13 for non-call CH when there is the call CH, and waits for any call CH to be idle when the signal showing 'busy' is transmitted from all call CH 2, 3,... Then, a command switching idle CH to control CH 1 is outputted to first and second switching parts 10 and 11 and switching is executed. Thus, switching can be executed without interrupting the call when the fault occurs in control CH. |
