In order to respond to communications disruptions during large-scale disasters, SoftBank has successfully conducted an experiment in providing communications from the sky by equipping a large unpiloted aircraft with a pod containing communications equipment for disaster response. By emitting radio waves from 3,000 meters in the air and building a communication area on the ground with a diameter of more than 5 km, it marked a major step toward the social implementation of emergency area coverage solutions in times of disaster.
In recent years, natural disasters such as huge earthquakes and super typhoons that have hit various parts of Japan have caused serious damage to terrestrial communications infrastructure. There have been a number of cases where base stations have collapsed or transmission lines have been disconnected, resulting in widespread communications failures and disrupting the transmission of evacuation information. SoftBank is promoting efforts to quickly build temporary communication areas in the event of an emergency and deliver communication methods to disaster-stricken areas and relief organizations.
In situations where terrestrial communication networks are disrupted, the idea of a flying base station that emits radio waves from the sky to recreate a temporary area is an effective solution. In March 2026, SoftBank, with the cooperation of Kuroshio Town, Kochi Prefecture, conducted a verification test of installing a communication equipment storage pod called a "DRU pod" (Disaster Relief Unit Pod) on a helicopter.
Based on these results, the company has begun social implementation using a large unpiloted aircraft system (Remotely Piloted Aircraft System (hereinafter referred to as ``large RPAS'') that is capable of long-distance and wide-range flight.
Manufacturing and certification process of Japan's first DRU pod for large RPAS
In order to operate a large RPAS as a communication platform for disaster response, the safety and reliability of the communication pod mounted on the aircraft must be improved. SoftBank designed and manufactured the DRU pod, which houses communications equipment and antennas, in Japan based on the design data and quality requirements of General Atomics Aeronautical Systems (GA-ASI).
During the manufacturing process, we conducted compatibility checks regarding the materials used and the manufacturing process, and confirmed that the product met the specified requirements. In the next stage of aircraft integration, after passing thermal environment and electromagnetic compatibility tests, the DRU pod was installed and safety tests were conducted on the ground and in the air. This test proved that the aircraft's maneuverability and stability were within safety standards when the pod was attached.
Furthermore, after a review by GA-ASI, airworthiness approval for the aircraft equipped with the DRU pod was obtained. We completed a demonstration experiment using a domestically designed and manufactured DRU pod for large RPAS, and are the first in Japan to successfully provide communications from the sky. Through this process, we gained valuable knowledge regarding the technology and certification needed to safely mount independently developed communication equipment on large unpiloted aircraft.
Radio wave irradiation from 3000m in the air Communication performance proven by demonstration experiment
This demonstration experiment was conducted with interagency cooperation between the Ministry of Internal Affairs and Communications and the Japan Coast Guard, using a large RPAS "Sea Guardian (MQ-9B)" manufactured by GA-ASI owned by the Japan Coast Guard. This initiative is being promoted as part of the commissioned research project ``Research and development of wireless communication technology for emergency area coverage during disasters'' under the ``Innovative Information and Communication Technology (Beyond 5G (6G)) Fund Project'' created by the Ministry of Internal Affairs and Communications at the National Institute of Information and Communications Technology (NICT).
Sea Guardian (MQ-9B) performed a circling flight while maintaining an altitude of 3000m above the coast of Kuroshio Town, Kochi Prefecture. A gateway consisting of an LTE base station and a frequency conversion repeater was placed on the ground. The 2.1 GHz band radio waves output from the ground base station were converted to 3.3 GHz band feeder link radio waves by a frequency conversion repeater and sent to the aircraft, and then reconverted to a 2.1 GHz band service link inside the DRU pod and transmitted to mobile terminals on the ground.
The key to protecting communication quality from aircraft shaking during flight was the gimbal technology built into the antenna inside the DRU pod. Even if a change in attitude occurred, the gimbal mechanism functioned to correct antenna directionality in real time, continuing to accurately capture the gateway and communication area on the ground.
By irradiating radio waves from 3000m above the ground, a temporary communication area with a diameter of more than 5km was established on the ground. A stable radio wave environment was continuously provided even during the aircraft's turning flight.
In the communication quality evaluation, we recorded a maximum download speed of 20Mbps and a maximum upload speed of 5Mbps (bandwidth 5MHz) outdoors. This speed is suitable not only for confirming safety, but also for local governments and rescue agencies to transmit videos and images from the scene and share information on the damage situation in real time.
Large unpiloted aircraft have the ability to stay in the air for longer periods of time and have a wider range than traditional helicopters and drones. Building a communication area that can stay in the air for long periods of time plays a role in quickly providing uninterrupted communication infrastructure even in the event of isolated villages or large-scale power outages.
Promptly delivering cutting-edge communication solutions from the sky
SoftBank will utilize this data and know-how to reduce the weight of the DRU pod, improve communication efficiency, and accelerate the construction of operational methods. We will continue research and development with the aim of early social implementation, centered on collaboration with related ministries, local governments, and aircraft manufacturers.
The emergency communication platform from the air, which utilizes large unpiloted aircraft, is a technological achievement that will increase communications resilience in Japan's disaster response efforts. SoftBank will promptly deliver cutting-edge communication solutions from the sky to protect people's lives from the threat of natural disasters.
