| 摘要 |
PURPOSE:To prevent line holding by restoring a channel depending on the presence of a voice signal or the presence of a busy tone(BT) as to the restoration of the channel from a mobile station. CONSTITUTION:A voice detection circuit 6, a timer circuit 7 and a channel control circuit 8 are connected to a channel 2 interconnecting a stationary station of an exchange network 1 and a stationary station (control station) 4 of a mobile communication system to allow the voice detection circuit 6 to detect a voice signal in the channel, and the channel control circuit 8 disconnects the channel to restore the system when no voice signal is in existence for a time designated by the timer circuit 7. Thus, holding of non-busy lines due to defect of restoration is avoided in restoration by a ground station or by a mobile station. Moreover, a BT detection circuit 9 is connected to the channel 2 to allow the BT detection circuit 9 to detect the presence of a BT, and when the BT is in existence in the channel, the channel control circuit 8 opens the channel for the restoration. Furthermore, the timer circuit allows the channel to be restored forcibly for the lapse of a prescribed talking time. |
