| 摘要 |
<p>PROBLEM TO BE SOLVED: To exactly reproduce the position of data on a time base even when a cell loss occurs on an ATM network in the case of converting an ATM cell into an STM signal. SOLUTION: A cell loss detecting circuit 10 decomposes the ATM cell into bytes, sends them to a memory 16 and detects the number M of lost bytes in the ATM cell. In the order of sending bytes from the cell loss detecting circuit, a sequence number generating circuit 12 generates a sequence number N of N=N+1 in the case of no loss or of N=N+M in the case of presence of loss. A write address generating circuit 14 generates a write address, and a read address generating circuit 18 generates a read address. A selector 24 sends either a byte read out of the memory or dummy data generated by a dummy data generating circuit 22 to the outside as an STM signal. A sequence number confirming circuit 20 checks the continuity of sequence numbers read out of the memory and when a sequence number is skipped, a dummy data inserting signal is sent to the read address generating circuit and the selector.</p> |
