Rakuten Mobile demonstrates satellite-to-cell call with AST SpaceMobile in Japan. Screenshot via Rakuten

Japanese mobile network operator Rakuten Mobile and AST SpaceMobile completed what they claim is the first-ever broadband video call between unmodified smartphones in Japan using a Low-Earth Orbit (LEO) satellite. This milestone comes ahead of Rakuten’s plans to launch the Saikyo Satellite Service powered by AST SpaceMobile next year. Rakuten Mobile announced the milestone, April 23.

Rakuten Mobile aims to expand connectivity across Japan – including mountainous regions, remote islands and in emergency situations. As part of the strategic partnership launched over five years ago, Rakuten Group and AST SpaceMobile aim to provide satellite-to-mobile broadband services (voice calls, video calls and more) in Japan starting in the fourth quarter of 2026.

The video call was completed on standard, unmodified smartphones available in Japan. The test was conducted after securing a preliminary license for an experimental test station. Rakuten Mobile plans to obtain a full experimental test station license and continue further communication testing.

During the test, radio waves were transmitted from Rakuten Mobile’s gateway earth station in Fukushima Prefecture to a BlueBird Block 1 satellite, which then relayed the signal to a smartphone. This enabled broadband communication between Fukushima and Tokyo using a standard communication app on an everyday unmodified smartphone, demonstrating direct satellite-to-smartphone connectivity.

“We are delighted to achieve the first-ever mobile broadband video call in Japan between a smartphone and satellite, proving this groundbreaking technology once again. In Japan, Rakuten Mobile is adopting various strategies to broaden our network’s reach. It can be challenging to extend coverage to remote and mountainous areas due to the difficulties in constructing base stations in these remote places. Japan is also a country prone to natural disasters and people’s awareness of the effects of climate change and increasingly severe disasters is increasing year by year,” Mickey Mikitani, chairman and CEO of Rakuten Group, said in a statement.