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an earth station to receive communications from the WINDS-compatible marine-based earth station installed on the research ship Mirai. e appearance and specica-tions of the 51M-VSAT are shown in Fig. 4 and Table 2, respectively. When WINDS is set in regenerative mode, the 51M-VSAT is able to establish communication lines capable of transmitting data at a maximum rate of 51 Mbps [4].4Experimental methods4.1Experimental network configuratione experiment was carried out within range of the WINDS multi-beam antenna (MBA) [4]. A communication line was established using the MBA beam for the Chubu Region―which was received by the WINDS-compatible marine-based earth station traveling at sea―and the MBA beam for the Kanto Region which was received by the 51M-VSAT in Kashima. e experimental network con-guration is illustrated in Fig. 5.Each earth station is connected to a telephone confer-ence system and a PC to measure throughput. e station on the ship is also connected to a second PC which logs antenna movements and the C/N0 (carrier-to-noise power ratio) levels of beacon signals from the satellite.4.2Experimental methods(a) Experiments to conrm satellite tracking perfor-mancee WINDS-compatible marine-based earth station can collect data on antenna movements, the C/N0 levels of beacon signals received from the satellite, the station’s loca-tion and its satellite tracking accuracy. We evaluated the satellite tracking performance of the station in relation to the eects of ship movement and waves.(b) Experiments to conrm data transmission charac-teristicsWe connected PCs to the IDUs (indoor units) of the earth stations both on the ship and in Kashima to measure the throughput of each station. e measurements were then used to analyze the transmission characteristics of TCP (Transport Control Protocol) communication between the two stations. ese PCs, which run a Linux operating system, were used to evaluate congestion control techniques suitable for a time delay environment. We also examined the transmission of UDP (User Datagram Protocol) com-munications, which are used to transmit image and audio data. In addition, we analyzed transmission characteristics of TCP and UDP communications using iperf [6].5Experimental results5.1Satellite tracking characteristics of the WINDS-compatible marine-based earth statione ship travelled continuously and was constantly af-fected by waves during the experiment. We investigated the relationship between antenna movement and the C/N0 levels of beacon signals from the satellite while the ship AntennaOffset parabolic antenna(φ1.2 m)FrequencyTX: 27.5 – 28.6 GHzRX: 17.7 – 18.8 GHzPolarized waveLinearly polarizedAntenna gainTX: 47.6 dBiRX: 44.0 dBiOutput power40 WG/T18.9 dB/KData rateTX: 1.5/6/24/51 MbpsRX: 155 MbpsTabT2　Various element of 51M-VSATFiF4　External view of 51M-VSATFiF5　Configuration diagram of experiment network PC for throughput measurement TEL conference systemKanto beam of MBA The earth station on board vessel for WINDS 51M-VSAT Chubu beam of MBAPC for system log PC for throughput measurement TEL conference system 1533-10 Experiment Report of Satellite Communication at the Ocean