Currently, diverse initiatives are underway both in Japan and internationally to evaluate various wireless technologies in preparation for the commercial launch of 6G (sixth-generation mobile communication systems). In particular, the development of a "wide-area, three-dimensional next-generation wireless communication infrastructure" -- extending from the ground to the stratosphere, and further into low Earth orbit (LEO) and outer space -- is attracting significant attention as a crucial element supporting future social infrastructure. At this workshop, experts delivered presentations on the latest trends in wireless communication technologies spanning land, air, and space -- including ultra-high-speed mobile communications, wide-area communications utilizing HAPS (High-Altitude Platform Stations), LEO satellite networks, and SAR (Synthetic Aperture Radar) observation solutions. Through these presentations, participants discussed the value these technologies bring to social infrastructure and industrial applications.

Dr. Koide from JR Central presented on wireless communication systems for ultra-high-speed railways. He detailed the challenges of wireless communication in superconducting maglev trains traveling at speeds of 500 km/h, as well as various communication applications such as train control, passenger services, and vehicle monitoring. He also introduced technologies for ensuring quality and redundancy by combining space diversity and site diversity.

Dr. Kishiyama from Space Compass gave a presentation on wide-area communication systems that utilize unmanned aerial vehicles (UAVs) navigating the stratosphere as HAPS wireless base stations. Taking into account the operational characteristics and challenges of the aircraft, he presented studies on optimizing operational scenarios and strategies for using different aircraft models. Furthermore, he highlighted the successful demonstration test in Kenya, the development of regenerative payloads, and considerations for implementing MIMO and beamforming technologies.

Dr. Inoue from Axelspace gave an explanation on the development and demonstration of optical communication capabilities in small LEO satellite constellations, focusing on the design and verification of inter-satellite network functions, orchestration services, and ground gateway systems. He shared their efforts regarding the optimization of satellite network routing algorithms -- encompassing route selection, fault detection, handover, and data multiplexing -- alongside simulations and actual hardware testing.

Dr. Horie from Synspective introduced their SAR constellation satellite system. He provided an easy-to-understand explanation of three observation modes using 100 kg-class small satellites, as well as high-resolution, high-frequency observation solutions achieved through the coordination of multiple satellites.

All four presentations were highly compelling, incorporating evaluation test results and experimental data. The workshop provided a deep understanding of how the latest wireless communication technologies -- cutting across land, air, and space -- will play a major role as a new social infrastructure. It proved to be a highly beneficial opportunity for participants to deepen their understanding of the future utilization and challenges of wireless network technologies.