| 摘要 |
PROBLEM TO BE SOLVED: To judge whether mute compression or a line fault is caused by transmitting a fault monitoring cell in a prescribed period when a part without sound exceeds a prescribed time and executing judgement based on whether or not the fault monitoring cell is detected in a prescribed time from a cell which previously arrives. SOLUTION: When a cell transmission interval monitoring timer part 4 detects that a mute part exceeds a prescribed time so as to continue, the control part 3 of a transmitting part 30 which converts a voice signal into a cell and transmits sounding part outputs a dummy cell where a cell classification code is made to be a PVC fault monitoring status as an ATM cell 16. In the meantime, the cell-converted voice signal is resolved and the original voice signal is reproduced in a receiving part 40. In the part 40, a cell reception detecting part 5 receives the ATM cell 16, identifies the cell classification code and outputs an ATM cell conversion signal 17 having the cell classification code and a cell resolving part 7 keeps mute reproduction when the fault monitoring cell is detected within a prescribed time from the cell which previously arrives and judges that the line fault occurs unless the fault monitoring cell is detected within the prescribed time. |
