— Major Step Toward Realization of 5G Communication from Stratosphere —

SKY Perfect JSAT Corporation, NTT DOCOMO, INC., the National Institute of Information and Communications Technology (NICT) ,and Panasonic Holdings Corporation (Panasonic HD) jointly announced today that they have successfully conducted a 5G communication verification test in the 38GHz band¹ from an altitude of approximately 4km using a small Cessna aircraft operated by Kyoritsu Air Survey Co., Ltd. simulating the eventual use of High-Altitude Platform Stations (HAPS) ². The demonstration was the first of its kind in the world.

In this groundbreaking trial to demonstrate the practical application of 5G feeder link³ and backhaul line⁴ for HAPS, a Cessna aircraft was equipped with newly developed communication equipment (“Cessna onboard station”) that is expected to be deployed eventually in HAPS. Additionally, a lens-type antenna with an auto-tracking function was used as the HAPS ground station (“ground station”).

The trial established an aerial relay backhaul line between the Cessna aircraft, flying at altitude of approximately 4km, and three ground stations, using the 5G New Radio (NR) standard⁵ with 38GHz band radio waves, which is a novel approach for terrestrial 5G networks. The achievement of multiple backhaul line consisting of aerial relays using the 5G NR standard with 38GHz band radio waves was a world first in telecommunication technology⁶.

With 5G evolution underway and 6G implementation on the horizon, various efforts are being made to expand coverage areas. Non-Terrestrial Networks (NTN)⁷ using HAPS is a promising technology for such expansions, so the results from this demonstration will help accelerate the practical application of HAPS networks.

The four organizations involved in this project are committed to continuing their joint efforts, aiming at the early delivery of 5G from the stratosphere via an NTN using HAPS.

The demonstration is part of a project focused on wireless communication systems using HAPS led by Japan’s Ministry of Internal Affairs and Communications ⁸.

¹ 38.0-39.5GHz frequency band was designated for HAPS fixed communication at 2019 World Radiocommunication Conference.
² Radio station onboard unmanned aircraft capable of flying in the stratosphere up to several months and equipped with repeaters, etc. to cover a 100-200km diameter for the skies, seas and unpopulated/mountainous regions where coverage has been economically unfeasible.
³ Relay communications between HAPS and ground station.
⁴ Fixed line that supports high-speed, high-capacity transmission between wireless base stations and core mobile network. The Core mobile network acts as a command center, managing authentication, authorization, and communication sessions (Control Plane). It also transfers data between the application server outside the core network and the terminal (User Plane).
⁵ New 5G wireless access technology, developed by 3GPP project in which various national standardization bodies are working to coordinate mobile-communication specifications.
⁶ As of April 3, 2024, according to research conducted by Panasonic HD.
⁷ A system that utilizes a variety of communication platforms, such as satellites, HAPS, drones, etc., to establish a multi-layered connection across different spatial dimensions, including sea, air, and space, extending beyond terrestrial boundaries.
⁸ Core plan of this R&D:  https://www.soumu.go.jp/main_sosiki/joho_tsusin/eng/pressrelease/2020/6/15_1.html