| 摘要 |
<p>PURPOSE:To attain monitor effective to the control of a packet transmission line by calculating a deviation of a detection time of a valid cell in addition to the condition of not in excess of n-cell in m-cell time. CONSTITUTION:An output of a cell detection circuit 2 is inputted to an addition input of an up-down counter 4 and the content of the counter 4 is number of cells detected in the preceding m-cell time. When the content exceeds a threshold level (n), an inhibit output is sent. An input counter circuit 8 counts a valid cell number detected for an m'-cell time each and gives the result to an arithmetic circuit 10. A square circuit 11 of the circuit 10 squares the number from the circuit 8 and the result is accumulated by an up-down counter 13. On the other hand, a delay output of the circuit 3 is inputted to an output counter circuit 9 and the value for each m'-cell time is counted and the result is squared by a square circuit 12 and the result is given to a subtraction input of the counter 13. The counter 13 stores the square accumulation value over the preceding m-cell time and the result is compared with a 2nd threshold level n', and when the count exceeds the n', a 2nd comparison discrimination circuit 16 sends a discrimination output.</p> |
