AT&T and AST SpaceMobile achieve first cellular-to-satellite handoff, cutting switch time to milliseconds

A seamless switch between two networks

AT&T and AST SpaceMobile said they demonstrated a seamless handoff from a ground-based cellular network to a direct-to-device satellite network on the morning of October 21 near Granite Falls, Washington. The companies call it an industry first. The goal is to keep calls and data connections alive as phones move out of tower coverage.

Who makes the switch work

AT&T operates the terrestrial network, while AST SpaceMobile runs the satellite network designed to talk directly to standard smartphones. The technology coordinating the transition comes from Ericsson and Nokia:

• Ericsson provided AT&T with combined radio and core network technology plus intelligent network automation; according to the company, this cuts handoff times from seconds to milliseconds.
• Nokia supplied radio access technology and mobility software for AST SpaceMobile's satellite network.

How it differs from earlier tests

AST SpaceMobile's BlueBird satellites had previously supported voice calls, texts and video calls on ordinary phones. This test focused on a different problem: transferring a connection between two networks built on very different infrastructure. The companies aim to make satellite connectivity work as an extension of the existing mobile network rather than a separate service users must activate.

Who benefits

The approach matters where conventional cellular infrastructure is hard to build or maintain: remote communities, highways and disaster-hit areas. AT&T says the integration could keep customers, first responders and essential workers connected where traditional coverage is limited.

Commercial use is still ahead

The technology is not yet ready for widespread commercial use. Robert Walters, AT&T's senior vice president of network, called the handoff a significant milestone while noting that further testing is needed. The next phase is expected to include beta services under real-world conditions. The companies have not announced a firm commercial launch date for the seamless handoff service.