AT&T official updates satellite-direct-to-device progress, challenges

Satellite-direct-to-device technology can work and potentially will be “revolutionary” for public-safety communications, but several questions still need to be answered through testing that will be conducted next year and into the future, according to a member of AT&T’s FirstNet team.

Mohammad Baig, AT&T’s lead market development manager for FirstNet, said the satellite-direct-to-device technology could solve a key outdoor-coverage issue that many public-safety officials have had with LTE connectivity for years.

“How do we take connectivity and deliver it directly to your regular, unmodified smartphone in those areas we’ve not [covered with a terrestrial network]?” Baig said during a presentation last month at APCO 2024 in Orlando. “What you’re looking at here is something that is revolutionary … cutting edge. The basic idea here is to have an LTE device—in our case, a FirstNet device—that connects via that low-Earth-orbit satellite without modifying that device … connecting to a gateway location and then directly to an operator core.

“The goal here is to give public-safety [agencies] the ability to have basic connectivity—basic voice, messaging and so on—because that’s the challenge today in uncovered spaces, where you have to use expensive devices and expensive hardware.”

Baig expressed confidence that satellite-direct-to-device service will work, citing tests that AT&T has conducted with its partner AST SpaceMobile, as well as by others in the industry.

“This architecture has been designed so that your device—your regular device—will work,” “There have been technology trials that have proven that we have been able to close that link [from the device to a LEO satellite]. We’ve done it, Lynk has done it, SpaceX/T-Mobile have done it, so the technology’s there.

“Whether we can scale this, I think, is the next big question.”

One of the most promising aspects of satellite-direct-to-device technology is that it allows unmodified cellular devices to connect to low-Earth-orbit (LEO) satellites that act as cell towers in space. While the devices will not have to be altered physically, Baig said they may need software updates before communicating with satellites.

“One of the grounding, basic facts that all of us [carriers and vendors] are trying to achieve is to not have any modifications on the device—it will work with your regular iPhone,” Baig said. “Now, whether there are firmware updates or software pushes, that still remains to be seen. Because any time any operator launches a new service, there’s always some sort of software push, a roaming update or what have you.

“That probably will happen, because that’s an easy thing to do. But the goal is not to change the handset at all, from a physical hardware standpoint.”

AST SpaceMobile plans to launch its first five commercial LEO satellites during the fourth quarter of this year, Baig said. When these satellites are operational, AT&T—and presumably other global carriers that have partnered with AST SpaceMobile—will be able to conduct field trials, according to Baig.

One capability that needs to be tested is what happens when a user moves from within a carrier network’s terrestrial footprint to a location that can be connected only via satellite-direct-to-device technology—for instance, whether the call can be maintained during the transition or whether the user will need to restart the communication.

“The question is, in essence, how do you hand off from terrestrial to this [satellite direct to device]?” Baig said. “That’s a work in progress, admittedly, for all of us. We have thoughts on how to do that … All of us—not just AT&T—are trying to solve that exact problem. That’s a known gap that we’re going to have to figure out over the next nine months or so.”

In addition, Baig and other officials previously have stated that AT&T and AST SpaceMobile successfully have tested the FirstNet priority-and-preemption capability on LEO satellites in a laboratory setting but have not conducted such a test in a real-world environment.

AT&T—along with global carriers like Vodafone and Rakuten—have worked closely with AST SpaceMobile for years and helped conduct initial tests of the technology. AT&T formalized its relationship with AST SpaceMobile with a deal that was announced in May. Just a few weeks later, AST SpaceMobile also announced a partnership with Verizon.

In June, FirstNet Authority CEO Joe Wassel announced a “ubiquitous coverage” goal for the FirstNet nationwide public-safety broadband network (NPSBN), and many sources believe that satellite-direct-to-device technology could play a significant role in making this vision become a reality.