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to set the data volume to be transmitted in advance. us, this method enabled us to measure transmission channels’ maximum capacities without packet loss. Capacity mea-surements at dierent data rate settings are shown in Table 5. Changes in the WINDS communication line throughput were measured for one minute. e 24 Mbps setting results are shown in Fig. 15 as an example.Header data volume in UDP communication was lower than in TCP communication, indicating that UDP communication throughput is virtually the same as the theoretical network bandwidth when WINDS is set in re-generative mode. In addition, UDP communication throughput reached the preset data rate as soon as mea-surement began, and remained virtually constant with only slight uctuations as the ship traveled. us, we conrmed stable communication during this experiment.6ConclusionWe studied the satellite acquisition and tracking char-acteristics of a marine-based earth station during oceanic travel by a station-equipped ship. e satellite tracking performance of the station was satisfactory, indicating that both TCP and UDP communications functioned stably. We were able to maximize the capacity of the TCP communi-cation line using congestion control algorithms tuned to WINDS.An open ocean satellite communication system would oer the advantage of exible networking of multiple bases via satellite, enabling data to be transmitted at a constant rate between the bases no matter how distant they are from each other. A constant transmission rate can be achieved across the satellite communication range. In future studies, it will be important to develop compact, light and energy-ecient earth stations that can be used to establish communication lines with several Mbps of capacity not only in the WINDS MBA range but also in the APAA (active phased array antenna) range, which mostly consists of ocean areas [4]. We plan to test these earth stations on the ocean once they are developed, establish communica-tion lines with several Mbps of capacity, establish an oce-anic network and consider its eective use.AcknowledgmentOur oceanic experiments were carried out jointly with JAMSTEC. We thank the JAMSTEC personnel who pro-vided us with helpful advice regarding the loading of ex-perimental equipment onto the ship and NICT researcher activities on the ship.is research was conducted in conjunction with the JAMSTEC-led “Next-generation technology for exploration of ocean resources” project being conducted under the auspices of the Cross-ministerial Strategic Innovation Promotion Program (SIP) sponsored by the Council for Science, Technology and Innovation.ReferenceR1Norihiko Katayama, Naoko Yoshimura, Takashi Takahashi, and Morio Toyoshima, “Conceptual Design of High-Speed Satellite Communication Equipment for ASV,” 21st Ka and Broadband Communications Conference, October 2015.2Norihiko Katayama, Naoko Yoshimura, Hideo Takamatsu, Susumu Kitazume, Yosuke Takahara, John Logan, and John Ness, “Development of Ka-band mobile communications platform for Ocean Broadband Communciations,” ICSSC2015, September 2015.3Takashi Takahashi, Naoko Yoshimura, Akira Akaishi, Norihiko Katayama, Morio Toyoshima, Naoto Kadowaki, Shojiro Ishibashi, Tatuya Fukuda, and Hiroshi Yoshida, “THE TELE-OPERATION EXPERIMENT OF THE HYBRID REMOTELY OPERATED VEHICLE USING SATELLITE LINK,” International Conference on Ocean, Offshore and Arctic Engineering (OMAE2015), June 2015.4Journal of the National Institute of Information and Communications Technology : Special Issue on Wideband InterNetworking Engineering Test and Demonstration Satellite (WINDS), vol.53, no.4, December 2007.5Akira Akaishi, Takashi Takahashi, Kazuyoshi Kawasaki, Norihiko Katayama, Byeong-pyo Jeong, and Toshio Asai, “Ka-band Broadband Mobile Earth Station for WINDS Satellite,” ICSSC2015, September 2015.6https://iperf.fr/7Norihiko KATAYAMA, Toshio ASAI, Kazuyoshi KAWASAKI, and Takashi TAKAHASHI, “A Study on TCP Window Size Control Method Suitable for WINDS Regenerative mode,” IEICE Technical Report, August 2012.8http://www4.ncsu.edu/~rhee/export/bitcp/cubic-paper.pdf9https://tools.ietf.org/html/rfc768WINDS linkNetwork bandwidth of UDP6Mbps4.6Mbps24Mbps18Mbps51Mbps36MbpsTabT5　Network bandwidth of WINDS link for UDPFiF15　Variation of network bandwidth for UDP 05000100001500020000020406080Time [sec] Throughput [kbps] 1573-10 Experiment Report of Satellite Communication at the Ocean