A consortium of major Japanese tech companies, including mobile operator NTT DoCoMo, has successfully conducted a trial of 5G communication in the 38 GHz band using a base station positioned 4 km above ground level.
This experiment is a critical part of Japan’s initiative to establish high-altitude platform stations (HAPS) for delivering 5G services from the stratosphere. Although the current test involved a Cessna aircraft simulating a HAPS, it marked significant progress by creating an aerial relay backhaul link between the aircraft and three ground stations using 5G new radio in the 38 GHz band—a global first.
In addition to DoCoMo, the trial included SKY Perfect JSAT Corporation, the National Institute of Information and Communications Technology (NICT), and Panasonic HD. These companies were selected by NICT for the HAPS project late last year, with Panasonic joining later.
The project’s goal is to provide direct-to-device mobile services via a space-based non-terrestrial network, contributing to the NICT’s beyond 5G program aimed at ensuring seamless coverage across air, sea, and space. The initial phase focuses on early commercialisation, addressing technical challenges, and demonstrating HAPS-based communication services over Japan.
The trial’s success is expected to expedite the practical implementation of HAPS networks. The participating firms are eager to achieve “early delivery of 5G from the stratosphere” but have not set a public deadline. Regular updates are anticipated as they push forward.
Space Compass, another entity in the overarching project, aims to launch HAPS services in Japan by fiscal 2025. While this trial concentrated on 5G, the companies are also progressing towards 6G, which will likely integrate various network types and technologies.
Research and development in 6G is a priority for NTT, especially after recent amendments to the NTT Law, which previously required the company to share its research findings, putting it at a competitive disadvantage globally. Now, NTT and its partners are keen to highlight their advancements in delivering 5G from space, positioning themselves for future technological leadership.
