AT&T and AST SpaceMobile say they’ve handed a live phone connection from a cell tower to a satellite without dropping it, which they call the industry’s first handoff between a ground network and a direct-to-device satellite network. The test took place on Wednesday, Oct. 21, at 8:15 AM PT outside Granite Falls, Washington, the companies announced on Monday, Nov. 2. It matters in Japan too, because AST’s satellites are the ones Rakuten Mobile plans to use for its own satellite-to-phone service before the end of this year.
Until now, satellite-to-phone services have mostly worked like a backup mode. Your phone loses the tower, eventually finds the satellite, and you start again. “Moving between ground and satellite coverage with other providers can mean a dropped call or interrupted connection,” AT&T wrote. In this test, the network moved the connection over in the background.
Who did what
Four companies were involved. AT&T supplied the ground network. AST supplied its BlueBird satellites, which connect straight to ordinary smartphones. Ericsson provided AT&T’s radio and core equipment, with network automation that AT&T says cuts transition times “from seconds to milliseconds.” Nokia supplied the radio access and mobility software that runs AST’s space network. Earlier tests had already sent voice calls, texts and video calls through BlueBird satellites to everyday phones, Investing.com noted. This one tackled the harder part, which is moving a session that’s already running from one network to the other.
“The successful handoff is a significant milestone, but it’s not the finish line,” said Robert Walters, AT&T’s senior vice president of network. The next step is beta service under real-world conditions, then commercial launch. AT&T hasn’t given a date for either. AST chief commercial officer Wayne Thorsen said the network is designed to let people make calls, use apps and stream content on the phones they already have, and to add resilience for first responders, according to Telco Magazine.
A caveat worth keeping in mind: this was one engineering test at one location, announced by the companies themselves. Broadband Breakfast and Telecompaper reported the result, but no independent measurements have been published.
The Starlink angle
This is the main rival to Starlink’s direct-to-cell business. AT&T and Verizon have lined up behind AST, while T-Mobile’s T-Satellite service runs on Starlink. SpaceX, meanwhile, is trying to become a carrier itself. Late last month the FCC cleared its move into mobile spectrum, and on Monday The Washington Post reported that SpaceX is in talks to buy or use Boost Mobile after the big three carriers turned it down (our Boost story).
The two companies are making very different bets. SpaceX flies a large constellation of smaller direct-to-cell satellites. AST is building far fewer, much larger ones. Rakuten says each AST antenna is about 223 square meters (roughly 2,400 square feet), about the size of a tennis court. A seamless handoff is the kind of thing carriers need before they’ll treat satellites as part of their network rather than an emergency extra, and AT&T now has a demo of it to show.
The EVX Take
Japan is the one market where both camps will soon be live side by side. KDDI’s au Starlink Direct and NTT Docomo’s docomo Starlink Direct (which passed 10 million users in under six months) already put Starlink on ordinary phones here, while Rakuten Mobile is preparing “Rakuten Saikyo Satellite Service” on AST. Rakuten made what it called Japan’s first video call between a low-Earth-orbit satellite and an off-the-shelf smartphone with AST in April 2025, and in August a Rakuten executive told ITmedia Mobile the company was putting on “the final touches” to launch within 2026. He claimed AST’s antennas are 30 to 40 times larger than rivals’, allowing broadband where others mostly do texts. That’s Rakuten’s sales pitch, not a measured result. But if the AT&T handoff carries over, Japanese users in the mountains or at sea could get a call that keeps going when the last tower drops away. That would give Rakuten, still the smallest of Japan’s four carriers, a rare technical edge, and it would give Starlink’s partners in Japan something to answer.
Sources: AT&T newsroom, Investing.com, Telco Magazine, Broadband Breakfast, Telecompaper, ITmedia Mobile (Rakuten), Rakuten Mobile press release (April 2025).
— The EVX News team
Featured image: The trail of AST SpaceMobile’s BlueWalker 3 test satellite crosses the night sky above the McMath-Pierce Solar Telescope at Kitt Peak, Arizona (2022). Image: KPNO/NOIRLab/IAU/SKAO/NSF/AURA / Wikimedia Commons (CC BY 4.0, cropped).
