duced, which can contribute to Space Situa-tional Awareness (SSA).■Technology for maritime / space broadband satellite communication network infrastructureThe conceptual designs of a next-gen-eration broadband communication satel-lite system were created, and contributed to starting the Engineering Test Satellite-9 (ETS-9) project, as a new broadband, ex-ible, and Ka-band / optical hybrid satellite communication system with 100 Mbps per user (Figure 3). We promoted research and development of the high-throughput satellite communication mission as commissioned research by the Ministry of Internal Affairs and Communications, and conducted re-search and development of satellite beacon transmission equipment called the Common Communication System (CCS) required for user experiments for satellite tracking. In addition, we completed the development of the satellite xed multi-beam communica-tion equipment, which is the ETS-9’s com-munications mission. Additionally, the pre-liminary designs for the satellite operation center for the terrestrial integrated network control and gateway Earth stations (main and sub-stations), and vehicle Earth stations were created. A simulator that comprehensively simulates the frequency / area / RF-optical feeder link switching control functions was developed, and the basic performance eval-uation of highly efcient operations control technology was conducted (see pp.8-9 of this issue).As a basic technology for future exi-ble on-board payloads, the effectiveness of the system error correction for the onboard digital beam former (DBF) feeder array was conrmed. Full-digital payload technologies onboard micro-satellites are studied, and the research and development of phased array technologies for satellite constellations were conducted. Additionally, a development of low-speed modems for IoT/sensor networks is promoted, which is expected to be new sat-ellite communication use cases.To provide broadband communication exibility / agility in areas with congest-ed or disrupted terrestrial communication networks in an emergency, in response to the Kumamoto Earthquake (April 2016) in Kyusyu, in collaboration with NerveNet, etc., the satellite communication link by the Wideband InterNetworking engineering test and Demonstration Satellite (WINDS) was established in Takamori Town to help ensure communications under the event of a disaster (Figure 4, Collaboration with the Resilient ICT Research Center). We also participated in disaster prevention drills, exchanged opin-ions, and improved the system. With regards to measuring Ka-band propagation charac-teristics of mobile Earth stations using the WINDS satellite, we measured the blocking effect of trees, etc., while moving the terres-trial on-the-move-vehicle station, and con-tributed to the standardization document.To promote satellite communications, we formulated a satellite 5G trial plan with the European Space Agency (ESA) to promote collaboration on the integration of satellites and 5G, and are promoting it as an NICT commissioned research project. We also set up a study group of 19 domestic organiza-tions on the integration of satellites and 5G, conducted studies on use cases, technical is-sues, etc., and released a white paper. At the “Space ICT Promotion Initiative Forum,” established on July 1st, 2020, the 5G / Be-yond 5G technology subcommittee plans to continue the discussion on the integration of satellites and 5G from our past studies (see pp.6-7 of this issue).■Future prospectsNICT will promote cutting edge research and development that will become world rsts, centered on space communication tech-nology, and will contribute to standardization activities such as ITU-R, AWG, and CCSDS, etc. Additionally, we will support Space ICT Promotion Initiative Forum’s activities pro-moting the formation of private communities and collaboration between different indus-tries in the private sector, including a variety of companies who are interested in space. We will show the direction for future research and development of Japanese communica-tion and broadcast satellites and demonstra-tion plans, and contribute to strengthening Japan’s competitiveness.Figure 4 WINDS Earth station, set up during the 2016 Kumamoto EarthquakeFigure 3 System image of a next-generation broadband communication satellite Figure 2 Successful world-rst basic experiments in optical communication and quantum cryptography between an optical ground station and a micro-satellite using SOTA5NICT NEWS 2021 No.1
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