Owning a 'Domestic' Satellite Network Directly Connected to Smartphones: Japan's Serious Choice Called J-LEO
There are still quite a few places in Japan where smartphones lose signal. In mountainous areas, on remote islands, and when disasters strike. If ground-based base stations are destroyed, a 99.9% population coverage rate becomes meaningless.
The technology to bridge that gap from space is 'D2D (Direct-to-Device).' Without using special equipment, the smartphone you currently have communicates directly with low-Earth orbit satellites—a mechanism that companies have been competing to commercialize since around 2024. In Japan, starting with KDDI last year, NTT Docomo also launched a direct communication service with Starlink in April 2026.
Amidst this trend, the Japanese government is set to make a selection as early as this month (June 2026) for 'J-LEO'.
A National Project Worth Approximately 200 Billion Yen
The Ministry of Internal Affairs and Communications (MIC) has prepared a subsidy of approximately 100 billion yen for J-LEO. However, this is support capped at half of the total cost. The selected operator must raise an equal or greater amount in private funding, bringing the total scale of the project to 200 billion yen.
What is important to note here is that this plan is not merely about developing communication infrastructure. The condition that it must be 'completely controlled and managed within Japan' is explicitly stated for J-LEO. Neither satellite network control nor data must pass through servers outside the country. This speaks to the essence of the project.
KDDI already provides 'au Starlink Direct' using Starlink, and Rakuten Mobile is also aiming for commercial service within 2026 in partnership with the US-based AST SpaceMobile. In fact, all four major Japanese carriers are moving toward some form of collaboration with foreign capital, including Starlink. As I have mentioned before, from the perspective of the 'democratization' of satellite communications, services have expanded rapidly due to competition among these companies.
Even so, the government does not view 'Starlink being available' as sufficient. Therein lies the logic of national strategy regarding space infrastructure.
From 'QZSS' to 'J-LEO'—A Consistent Commitment to Domestic Infrastructure
Japan's stance of wanting to own its satellite infrastructure is not something that started just now.
The Quasi-Zenith Satellite System (QZSS, Michibiki) is a classic example. To complement the accuracy of the US-operated GPS, Japan built its own satellite positioning network. This J-LEO project is situated in the same context regarding the intent to reduce dependence on foreign capital. However, there is one major difference: while QZSS was strictly a 'complement' to GPS, J-LEO requires an independent network that is entirely owned and operated by private Japanese companies.
The geographical characteristics of being an archipelago nation also support this decision. In Japan, where mountains and seas are intertwined and there are many remote islands, the risk of communication infrastructure malfunctioning during large-scale disasters is high. The concern about continuing to rely on satellites controlled from abroad has become a reality after events like the Noto Peninsula Earthquake.
A Three-Way Competition and the Critical 700MHz Band
The leading candidates competing for J-LEO are three alliances.
The 'Rakuten-AST Alliance' formed by Rakuten Mobile and AST SpaceMobile, the 'KDDI-SpaceX Alliance' between KDDI and SpaceX, and a third alliance joined by Canada's MDA Space. What is drawing attention now is the recent move by the MIC's council subcommittee to approve the use of the 700MHz band for satellite D2D.
Among the four major Japanese carriers, only Rakuten Mobile holds this 700MHz band exclusively. In that sense, this frequency band approval has become a major tailwind for the Rakuten alliance. Regarding AST SpaceMobile, I have detailed their technical capabilities—the BlueBird satellite series, which has the largest communication array in history—in a previous article.
On the other hand, the strength of the KDDI-SpaceX alliance is its track record. Starlink already has a history of test operations with the Japan Ground Self-Defense Force and possesses a satellite constellation of thousands of units worldwide. However, from the perspective of autonomous control and domestic management, the fact that SpaceX is essentially a 'foreign company' may cast a shadow over its evaluation.
The MDA Space alliance remains a 'wild card' whose Japanese partner's direction is difficult to read, especially with the last-minute news that Mitsubishi Electric was selected as a partner for the Ministry of Defense's next-generation GEO satellite.
The Moment 'Space Sovereignty' Becomes Reality
Securing frequency bands, keeping data management entirely domestic, and the operational deadline of March 2029—the requirements for J-LEO are quite high hurdles. Nevertheless, the reason the government is so serious about this is likely because satellite communication infrastructure is being positioned at the core of future security and economic security.
The EU is also moving forward with the construction of its own constellation called IRIS², steering toward restricting non-EU operators in the allocation of frequency bands. The movement to secure 'satellite communication sovereignty' is not unique to Japan.
In an era where smartphones and space connect directly, who will hold that 'connection'? J-LEO is Japan's answer to that question. The selection results at the end of this month will be a litmus test for the future direction of Japan's space policy.
Reference Articles
○ Japan Eyes Sovereign D2D Satellite Network (June 25, 2026)
○ Democratization of Satellite Communication: Toward an Era Where Everyone Is Connected (July 2, 2025)
○ A New Era of Space Communication Opened by the Largest Satellite Antenna in History—AST SpaceMobile's Challenge and Its Impact on the Japanese Market (December 25, 2025)
○ Redistribution of Frequency Bands—EU Declares 'Non-EU Operators Limited to One-Third' (Around May 2026)
○ Intensifying Competition! Companies Working on 'Direct-to-Smartphone' Satellite Communication Without Antennas (January 14, 2026)
○ 'docomo Starlink Direct,' a Direct Communication Service Between Starlink Satellites and Smartphones, to Launch on April 27 (April 2, 2026)