| 摘要 |
<p>PURPOSE:To put cell flow in order by removing fluctuation received from a transmission line to the cell of an ATM by calculating the scheduled sending time of a cell, which is provided with transmission permission, by a policing part and reading the relevant cell from a memory at that sending time. CONSTITUTION:The synchronism of cells on the transmission line is acquired by a cell synchronizing circuit 1, each time the cell arrives, cell header information is transferred to a policing part 2 and the cell is transferred to a memory 4. The policing part 2 stores an interval T of minimum cells and an allowable value tau of fluctuation for each kind of information, each time the cell arrives, the information is received from the circuit 1, and it is decided whether the cell violates a traffic contract or not. The decided result is reported to a cell outgoing time arithmetic part 3. A write control circuit 15 writes the cell, for which the outgoing time is decided by the arithmetic part 3, in the memory 4 at an address corresponding to that time but when the cell of the other information is already written at that time, the cell is written in the empty area in the nearest future direction. The memory 4 is provided with capacity just for 2tau cells, and a read control circuit 16 spriously operates the memory 4 as a FIFO by circulating a pointer on the memory address of the memory 4.</p> |
