Network system transmission control method

Abstract

To improve the method of scheduling data transfer requests based on the transfer completion times to the transfer addresses which are assigned to the data for which transfers are requested. A limit time is assigned as an attribute to the data for which transfer is requested from control system 1. The transmission station which becomes the data station (transmission control processing circuit 12) produces a transfer completion time, taking the limit time as the upper digit, the count value of counter 13 which counts a constant clock as the middle digit and the number inherent to the transmission station as the lower digit, and transfers to the transmission station, which becomes the master station, output request control information which includes the data packet length found from this transfer completion time and the data length to be transferred. The transmission station, which becomes the master station, (transmission control processing circuit 12 and reception control processing circuit 17) determines the order given to output permissions based on the transfer completion times, determines the number of output requests permitted based on the data packet lengths, and schedules output permissions for the output requests of multiple transmission stations.