抄録
In satellite communications using Wideband InterNetworking Engineering Test and Demonstration Satellite (WINDS), the throughput does not increase because of factors such as presence of a long delay environment and attenuation of signals by rain. One of the solutions for long delay environment is to enlarge the TCP window size. However, packet loss occurs when a signal is attenuated, and the throughput decreases with the retransmission time in TCP communications. Furthermore, the transmission efficiency worsens because of the increase in the number of retransmission packets when the TCP window size increases. In this paper, from the result of throughput measurement by changing TCP window size in the WINDS regenerative mode, the TCP window size which was suitable in purpose to maximize a throughput is presented.