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throughput, as shown in Fig. 10. When the quality of lines is high, it is possible to transmit data at 10 Mbps, conduct-ing CRC for all packets by hperf. In this section, we inves-tigate the maximum throughput of HpFP, which is transmissible during CRC for all packets by hperf.During the time of CRC, the error is not detected. In Figs. 14, 15 and 16, throughputs of HpFP are shown for the cases of the target throughput of 100 Mbps and 1,400 Mbps, respectively. e format of these gures is the same as that of Figs. 8 (a) and (b). ere is no essential dierence between the results in Fig. 14 (a) and Fig. 15 (a), which are obtained in implementing CRC. In addition, the target throughput is achieved in both experiments, which are the same as in Fig. 10 (a). On the other hand, the ef-fective throughput in Fig. 16 (a) is much smaller than the target throughput, which is the same level of Figs. 14 (a) and 15 (b).From these results, the possible maximum target throughput in the case of CRC for all packets during the data transmission in WINDS communication lines is 100 Mbps. e network condition may vary largely during even a small time interval for the WINDS with bent-pipe mode. erefore, CRC is necessary to ensure the reliability of data transmission. e eective maximum data trans-mission rate is 100 Mbps for the case of data transmission by HpFP, which simultaneously conrmed the reliability of data arrival.5ConclusionFor ultra-high speed (> 1 Gbps), TCP/IP-based satellite communication protocols have been developed and various high-speed transmission is being attempted by improving TCP [11]–[14]. In general, RTT is large in the transmission link of geostationary orbit satellites or deep space investiga-tion satellite. e RTT for geostationary orbit satellites is FiF14　Case of no CRC at target throughput of 100 MbpsFiF16　Case of CRC at target throughput of 1,400 MbpsFiF15　Case of CRC at target throughput of 100 Mbps(a)(b)(a)(b)(a)(b)3 Ultra-High-Speed Satellite Communication Technology174　　　Journal of the National Institute of Information and Communications Technology Vol. 64 No. 2 (2017)