ATM CELL TRANSMITTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a FIFO memory with a capacitance satisfying the whole quality classes without providing the FIFO memories at every virtual channel and also to prevent a hardware quality from being vast by providing quality classes in accordance with transmission delay permission quantity in ATM. SOLUTION: Cells are classified by quality class and stored in buffers 1n∼n and 21∼n . The cells are read out of the buffer of the quality class with high priority and shift is successively executed to the low-order ones. Otherwise a cell of the low-order class is inserted between the cells when there is a room in the transmission schedule of the cells in the high quality class with high priority. Thus, cell transmission which satisfies request quality as against transmission delay is executed with a small hardware quantity.