| 摘要 |
<p>PROBLEM TO BE SOLVED: To realize maximum transmission throughput at each occasion, depending on the quality of a channel during communication. SOLUTION: When a file is transferred using plural connections which are decided based on the window size of a transmission control protocol(TCP), a transmission delay time and a channel transfer rate, the number of times for retransmission of data generated accompanying deterioration in the channel quality is counted for each connection (s22) and when the number of times for retransmission within a prescribed time is increased, the window size is reduced (s23). When the number of times for retransmission within a prescribed time is increased further, the use of the concerned connection is stopped if necessary (s24, s25), untransmitted data in the connection window are recovered and registered again to attain transfer by another connection (s26), and the number of times for retranmsission within a fixed time decreases, the window size is extended (s29).</p> |
