Japan’s three major telecom operators fully embrace Starlink satellite direct-to-mobile service, and Rakuten chooses AST SpaceMobile to start from scratch

SoftBank (SoftBank, Tokyo Stock Exchange ticker: 9434) announced on April 2 that it will launch a satellite direct-to-device (Direct-to-Device, D2D) service, using Starlink satellite network from SpaceX, owned by Elon Musk. With this, all of Japan’s three major telecommunications carriers have confirmed entry into the satellite direct-to-device phone market, and the competitive landscape has officially taken shape.

Timeline of Japan’s three major telecommunications carriers

Service positioning: disaster communications and coverage for remote areas

SoftBank emphasized that this service is designed to ensure communication capabilities in scenarios where traditional terrestrial base station signals are poor (mountainous areas, remote islands, and at sea). When local infrastructure is damaged by disasters, it will support compatible devices to send and receive text messages via satellite, as well as conduct data communications for some applications. The service requires users to be outside SoftBank’s normal coverage area and with no buildings or hills nearby that block the satellite connection. It does not currently support voice calls or emergency calls (Japan’s 110 and 119).

KDDI is the telecom provider that first launched this type of service in Japan; its au Starlink Direct went live in April 2025. NTT Docomo chose to announce that docomo Starlink Direct would be available on April 27 on the same day SoftBank made its announcement, which is notable timing.

Rakuten takes a differentiated route: AST SpaceMobile supports voice calls

While the three major carriers collectively chose Starlink, Rakuten Mobile selected a partnership with AST SpaceMobile in the United States—an investment target of the Rakuten group as well. AST SpaceMobile’s technical strength lies in its support for voice calls and higher-speed data transmission, which differs from the current Starlink D2D capabilities that are limited to text and some data.

Implications for the market and investors

Unlike traditional satellite phones, satellite direct-to-device technology can be used on ordinary smartphones (limited to compatible models) without requiring dedicated hardware. Device requirements that support satellite communications may increase—for example, Apple iPhone models from after the iPhone 14 onward include satellite communication functionality.

For telecom carriers, the “peace of mind of being able to connect anytime, anywhere” is becoming a new dimension of market competition, no longer just a battle over network quality and pricing. Investors need to pay attention to how quickly each company rolls out its service, the pace at which compatible devices are expanded, and how significantly licensing fees affect profitability. SoftBank has not yet published detailed plans, and the subsequent specific proposals may become a key point to watch for the stock price.

This article: Japan’s three major telecom carriers fully embrace Starlink satellite direct-to-device phone service; Rakuten chooses AST SpaceMobile to go its own way; first appeared on Chain News ABMedia.