Advance satellite communications technology has been achieved through Wideband InterNetworking engineering test Satellite (WINDS) and Engineering Test Satellite 9 (ETS-IX) projects in these two decades in Japan. WINDS achieved Gbps-class transmission capability, wide bandwidth active phased array antenna in Ka-band, and high speed onboard switching technologies. ETS-IX is currently being developed to demonstrate flexible resource management capability with wide bandwidth digital channelizer and digital beam former in Ka-band. In this chapter, very high capacity optical communications technology being developed for feeder link applications of a very high throughput satellite is reviewed. Satellite communications are thought to be beneficial for 5G coverage expansion to the ocean surface, air and space, and some trials to integrate to 5G. ETS-IX will be used as an experimental platform for such technical trials based on European Space Agency-National Institute of Information and Communications Technology (ESA-NICT) collaborations. Based on these achievements and experiences, and taking into account the recent trend of satellite communications technology for VHTS, LEO constellations, HAPS, and so on, we have studied next-generation satellite communications technology.

Chapter Contents:

• 31.1 Introduction
• 31.2 WINDS
• 31.3 ETS-IX
• 31.4 Direction of Satcom R&D
• 31.4.1 Satellite communications in beyond 5G networks
• 31.4.2 Fundamental technology development for satellite networks in the future
• 31.4.2.1 Digital transponders
• 31.4.2.2 Optical space communications
• 31.5 Conclusion
• References

Inspec keywords: artificial satellites; internetworking; optical communication; satellite communication; broadband networks; antenna phased arrays

Other keywords: Japan; wide bandwidth digital channelizer; high speed onboard switching technologies; Wideband InterNetworking engineering test Satellite; Ka-band; flexible resource management capability; ESA-NICT collaborations; National Institute of Information and Communications Technology; advance satellite communications technology; European Space Agency; next-generation satellite communications technology; high throughput satellite; Engineering Test Satellite 9 projects; ETS-IX; high capacity optical communications technology

Subjects: Satellite communication systems; Computer communications; Antenna arrays