| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the capacity of memory when a performance managing cell is used. SOLUTION: A performance managing cell (FM cell) of forward direction, to which the count value of sent-out user cells is added, is sent out, this FM cell is received, cell damage or erroneous cell distribution is detected while using the count value of sent-out cells and the count value of received user cells performance managing cell of backward direction (BR cell) is generated based on the FM cell and sent out while adding the count value of sent-out cells and the count value of received cells to it. On the side where the FM cell is to be received, the data of difference between the count value of dent-out cells and the count value of received cells, which are found when the FM cell is received the last time, are read out of a memory part and the difference of these differential data from the difference between the count value of sent-our cells and the count value of received cells this time is defined as an identification value D. In the case of D=0, normal reception is discriminated, in the case of D<=2<15> , cell loss is discriminated and in the case of D>2<15> , erroneous cell distribution is discriminated.</p> |
