Japan's first direct-to-smartphone satellite broadband service, enabling voice, video, and data on unmodified LTE handsets via AST SpaceMobile BlueBird LEO satellites.
Rakuten Saikyo Satellite Service
Japan's first direct-to-smartphone satellite broadband service, enabling voice, video, and data on unmodified LTE handsets via AST SpaceMobile BlueBird LEO satellites.
Description
Rakuten Saikyo Satellite Service is Japan's first commercial satellite direct-to-device (D2D) connectivity service, developed exclusively for Japan by Rakuten Mobile in partnership with AST SpaceMobile (NASDAQ: ASTS). The service leverages AST's BlueBird low Earth orbit (LEO) satellite constellation, which carries massive phased-array antennas capable of communicating directly with standard, unmodified LTE smartphones — no special device, application, or SIM swap is required.
In April 2025, Rakuten Mobile and AST SpaceMobile completed Japan's first satellite-to-smartphone two-way broadband video call using a BlueBird Block 1 satellite and an off-the-shelf LTE handset in Tokyo. The gateway earth station transmitting the signal was located in Fukushima Prefecture, demonstrating end-to-end space-based connectivity over Japan.
The service is designed for seamless handover: when a Rakuten Mobile subscriber moves beyond the reach of the terrestrial 4G/5G network — into mountainous areas, remote islands, or disaster-affected zones — the device automatically switches to satellite coverage without user action. Supported use cases include voice calls, video calls, messaging, social media, and video streaming.
Commercial launch is targeted for Q4 2026 with limited coverage, scaling to nationwide in fiscal year 2027. The Japanese government has committed approximately ¥150 billion ($922 million) to the joint venture between Rakuten Mobile and AST SpaceMobile supporting satellite procurement and ground infrastructure.
Specifications
| Service type | Satellite direct-to-device (D2D) broadband |
|---|---|
| Satellite constellation | AST SpaceMobile BlueBird LEO |
| Orbit | Low Earth Orbit (LEO) |
| Device compatibility | Unmodified standard LTE smartphones |
| Supported services | Voice calls, video calls, messaging, data (social media, streaming) |
| Coverage target | 100% Japan population including remote islands and mountains |
| Handover | Automatic seamless switch from 4G/5G terrestrial to satellite |
| Ground infrastructure | Rakuten Gateway Earth Station, Fukushima Prefecture |
| Commercial launch | Q4 2026 (limited coverage), FY2027 nationwide |
| Government investment | ¥150 billion (~$922M USD) from Japanese government |
| Exclusivity | Exclusive AST SpaceMobile partner for Japan |
| Spectrum | 700 MHz (Rakuten Mobile exclusive Japan allocation) |
