A Japanese consortium has made history by successfully demonstrating 5G communication from a height of 4 km in the frequency range of 38 GHz. This groundbreaking experiment, the first of its kind in the world, was carried out by four organizations: Sky Perfect Jsat Corporation, NTT Docomo, National Institute of Information and Communication Technologies (NICT), and Panasonic Holdings Corporation.
The test utilized a Cessna aircraft to simulate a station on a high-altitude platform (Haps) as part of a project led by the Ministry of Internal Affairs and Communications of Japan to develop wireless communication systems based on HAPS.
Using the 5G New Radio (NR) standard with radio waves in the 38 GHz range, the test successfully established an air relay line between the Cessna aircraft and three ground stations. This achievement represented a global breakthrough in telecommunication technologies and a new approach for terrestrial 5G networks.
The aircraft was equipped with a new communication system, and a Linz antenna with a car gasket function acted as a HAPS ground station. The technology enabled the establishment of a data transfer channel between two ground stations, showcasing the operation of a relay line of the 5G ground network through the air relay.
For the integration of Haps in the 5G and 6G network, flexible switching and control of lines between the ground and stratosphere network will be necessary. The test demonstrated seamless data transfer without interruptions, even when moving equipment between the coverage zones of base stations.
One challenge addressed during the experiment was the impact of weather conditions on radio waves in the 38 GHz range, particularly the effects of rain. The test successfully implemented an algorithm to compensate for signal weakening due to rain, enhancing synchronization with the 5G network.
The data collected from this demonstration will support the practical application and standardization of HAPS technology, guiding future technical development and performance enhancements. The Japanese consortium aims to leverage these results to implement 5G communication services through HAPS, ultimately contributing to the development of Non-Terrestrial Networks (NTN) that connect sea, air, and space beyond traditional ground boundaries.