Japan's Rakuten Mobile says it plans to offer a satellite-based mobile service that will support standard smartphones starting from 2026, although the satellites to provide this capability have yet to be launched.

Rakuten, one of four mobile networks operating in Japan, said it aims to provide satellite-to-mobile services across the country that can be used not only for text messages but also broadband communication, voice and video calls, using commercially available smartphones.

The company's partner on this project is satellite operator AST SpaceMobile. The outfit has already proven its technology works using a test satellite called BlueWalker 3, with which the pair claimed to have made the first ever space-based voice call using unmodified phones last year.

The partnership also achieved initial download speeds of 14 Mbps, and successfully made 4G video calls and 5G broadband connections using the test satellite operating with 5 MHz channels.

AST SpaceMobile claims to have "over 40 agreements and understandings with mobile network operators globally" relating to its satellite service.

However, while Rakuten is hoping to start the service in 2026, it is coy about the timing because AST SpaceMobile has yet to launch any of the fleet of BlueBird commercial satellites through which the service will operate.

"The actual timing of the initiation of any such service and the scope of such service is uncertain and is subject to a number of factors, including those that are outside of the control of Rakuten and AST SpaceMobile," it said in a statement accompanying the announcement.

AST SpaceMobile previously said it was aiming to launch the five BlueBird satellites during this first quarter of 2024, but press reports have hinted that this may now have slipped to the second quarter. This wouldn't be the first delay, however, as the company had previously aimed for the end of 2023, which was itself said to be a delay of about six months.

We asked AST SpaceMobile when it now expects to loft the satellites, and will update if we get an answer. The launch is expected to use a SpaceX Falcon 9 rocket.

Once available, those BlueBird commercial satellites are designed to support 40 MHz channels, potentially enabling data transmission speeds of up to 120 Mbps, at least according to AST SpaceMobile.

Rakuten said it was aiming to offer a satellite service because Japan is a country with a high risk of natural disasters and many remote islands and mountainous regions that are poorly served by other communications networks.

"Rakuten Mobile is committed to expanding mobile connectivity across Japan," said Rakuten Group Chairman Hiroshi "Mickey" Mikitani.

The threat of natural disasters, coupled with the effects of climate change, has heightened public awareness of the importance of mobile connectivity for daily life, he claimed, adding: "We are proud to partner with AST SpaceMobile to bring their cutting-edge solutions to Japan by realizing satellite-to-mobile services, ensuring our customers would potentially enjoy mobile connectivity across Japan."

Vodafone is another company that intends to offer commercial services using AST SpaceMobile, but it has not so far offered a date, and US carrier AT&T is also a partner. Both were joined by Google in announcing $206.5 million in financing for the satellite operator last month.

Others are also looking to get a foothold in the satellite-based mobile business. SpaceX's Starlink started advertising a Direct to Cell satellite phone service last year, claiming it would be up and running in 2024. The company confirmed a successful test of its platform last month, following the launch of the first six satellites capable of supporting the service early in January. ®

https://www.theregister.com//2024/02/16/rakuten_mobile_space_cell_service/