| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable a cell transference of a low preference class that is good in delay quality by recognizing a delay time of a leading time of a low preference class accumulated in a buffer and selecting the optimal push out system in accordance with the delay time. SOLUTION: When there is no room in a buffer and a cell of a low preference is stored, a residence time of the cell is calculated by a residence time calculation part 13 on the basis of a counter value written in a header of the leading cell of low preference stored and information on the present counter value. Then, if a calculated residence time is larger than a preset residence time threshold, a cell write part 5 rejects the leading cell of the low preference class and if the calculated residence time is smaller than the threshold, the cell at the end of the low preference class is rejected. After the cell of low preference class is rejected, a cell of new high preference class is stored in a memory at the end of a high preference class and the leading cell of the low preference class is added to the back of the cell of new high preference class.</p> |
