AT&T exec Sambar discusses tests with AST SpaceMobile, notes FirstNet implications

AT&T acknowledged its testing of AST SpaceMobile’s satellite-direct-to-phone technology and cited its potential impact in filling coverage gaps, particularly as an augmentation to the FirstNet terrestrial system designed for U.S. first responders.

In a video that was released today, AT&T Network President Chris Sambar (pictured above) said AT&T “is really excited about the opportunity to test the integration of our terrestrial mobile network with the AST solution,” noting AST SpaceMobile’s BlueWalker 3 satellite and possible implications of satellite-direct-to-phone service for customers.

AST SpaceMobile launched the BlueWalker 3 low-Earth-orbit (LEO) satellite earlier this year and announced its unfolding last month. Testing of the BlueWalker connectivity with carriers is scheduled to being early in 2023, according to AST SpaceMobile.

“The reality is it’s impossible to cover every square inch of America with any single technology, but we believe we can come really, really close with the combination of terrestrial networks and direct-to-cell satellite networks,” Sambar said during the video. “And we think that this relationship with AST is going to give us the ability to do that, really extend our network to a lot of different areas that we won’t necessarily connect to today.

“I think there’s some great potential in the BlueWalker 3 mission, some things that we haven’t even imagined yet. Just imagine the peace of mind that we can give consumers, first responders after disasters, remote agriculture, remote machinery. And then there’s another whole host of possibilities out there that we can look at.”

FirstNet’s nationwide public-safety broadband network (NPSBN) was one notable use case highlighted during video by Sambar, who led AT&T’s FirstNet team when it won the NPSBN contract in 2017. With satellite-direct-to-phone technology, AT&T could deliver broadband connectivity immediately to first responders, even in areas beyond the coverage footprint of terrestrial network, he said.

“FirstNet has the largest coverage of any carrier in the United States; but of course, there’s areas that we don’t cover and where they [first responders] need our help sometimes,” Sambar said. “We have deployable assets that we bring out to cover these areas when they call us, but those take a little bit of time … What would mean a lot to us is if we could turn on that connectivity immediately.

“[With] the space-based mobile network that AST is building, just imagine the possibility—when they need coverage, it’s immediately there: two-way connectivity, text, voice, data, and even location tracking. What a terrific opportunity to be able to provide that to first responders as an augment to the FirstNet program.”

Sambar noted that Dallas-based AT&T began working with AST SpaceMobile in 2018 and that the carrier’s personnel has visited the satellite-direct-to-phone company’s headquarters in Midland, Texas, “multiple times” to get answers to numerous technical questions. In fact, AT&T representatives were in Midland during the BlueWalker 1 testing that demonstrated that the satellite-direct-to-phone technology could work.

“We’ve been really impressed with the AST team and the thought that they put into it and the working relationship between our two teams on all these deep technical subjects,” Sambar said. “We also visited during the first vehicle that they sent up in space and conducted some testing together between our two companies. I think the BlueWalker 1 experience is what told us that, ‘You’re really on to something here.’

“The call testing actually worked, so [it was] really impressive. And I think that’s when the AT&T team really started to buy in and believe that these folks are onto something. They’ve got some really smart engineers over there, and it’s been a great collaboration.”

AT&T was initially listed as one of the first carriers supporting AST SpaceMobile in its pursuit of satellite-direct-to-phone technology, but the U.S. carrier giant was conspicuously quiet about the relationship for some time—a stark contrast to international wireless carrier Vodafone, which did a video about AST SpaceMobile in February.

AT&T expressed support publicly for AST SpaceMobile after the FCC approved the BlueWalker 3 tests on spectrum used by AT&T—notably, 700 MHz Band 14 airwaves licensed to the FirstNet Authority—in the spring. Sambar’s video released today is another sign of AT&T’s support of AST SpaceMobile’s efforts in the satellite-direct-to-phone arena.

Of course, AST SpaceMobile is not the only company attempting to provide satellite-direct-to-cell-phone services.

Lynk Global has a similar business model—partnering with cellular carriers with sub-1 GHz spectrum to fill coverage gaps—but a different system architecture. While AST SpaceMobile plans to provide cellular broadband service globally with 168 LEO satellites, Lynk plans to deploy thousands of smaller LEO satellites to support eventual broadband connectivity, although its initial offerings will be text-only services.

Lynk also is the first satellite-direct-to-cell-phone company to receive an FCC license for commercial operations, although the license only applies to 10 satellites.

Other significant developments in the satellite-direct-to-cell-phone arena include T-Mobile and SpaceX announcing plans in August to provide connectivity leveraging 1.9 GHz spectrum. In September, Apple announced that it has teamed with Globalstar to provide an emergency text service—known as Emergency SOS—via satellite on 2.4 GHz spectrum for iPhone 14 users.

LEO satellite service is not new to the commercial or critical-communications sector, as companies like Starlink and OneWeb has been operating for years under a traditional satellite model that requires a special satellite receiver on the ground to access the connectivity offering.

In contrast, the satellite-direct-to-phone providers offer connectivity that is accessible to users via their unmodified cellular devices, with the LEO satellite effectively acting as a “cell tower in space” and the providers of the service acting as a roaming partner to existing carriers.

For the critical-communications industry, this satellite-direct-to-phone technology has the potential to address some of the greatest remaining concerns associated with making LTE and 5G “mission-critical-grade” technologies.

Most agree that broadband connectivity via LTE and 5G delivers better performance when connected to a terrestrial network than traditional land-mobile-radio (LMR) systems, but LMR technology has been perceived as superior when terrestrial towers are not available.

LMR systems allow for “graceful degradation” in functionality as terrestrial towers lose their backhaul connections or are unavailable entirely. Even if no LMR network infrastructure is available, LMR users can switch to simplex mode—also known as “direct mode”—and communicate with others within a range of miles in an outdoor setting, depending on the power level of the radio and radio-frequency (RF) propagation environment.

LTE has a direct-mode standard known as Proximity Services (ProSe), but it has not gained industry acceptance—no devices being manufactured today offer the capability. While Samsung has proven that ProSe works, the range of the direct-mode technology is not what public-safety users have grown to expect in the LMR world, largely because of the physics associated with using low-power (200 milliwatt) devices and internal antennas.

In contrast, the satellite-direct-to-phone technology—if it works as designed—would allow users to maintain at least a roaming-like experience with their smart devices. This would provide greater system reliability, allow for minimal degradation without user interaction, and support “off-network” communications with infinite range, at least when the user is outdoors.

Another important feature is the business model being pursued by satellite-direct-to-phone providers. Satellite connectivity historically has been too expensive for budget-conscious public-safety agencies, based on the costs to launch satellites and pay for special dishes or devices to receive the satellite signal.

Under the satellite-direct-to-phone model, the LEO satellite provider partners with a commercial carrier and could earn at least some revenue from every participating subscriber—potentially billions of people worldwide—instead of depending solely on the military, maritime travelers and outdoor enthusiasts for regular usage. In addition, the regular cadence of satellites being launched by companies like SpaceX has dropped the per-satellite launch costs dramatically, according to sources in the sector.

As a result, industry sources have told IWCE’s Urgent Communications that the cost of the satellite-direct-to-phone service potentially could be relatively small and likely would be included in a monthly bill from a cellular carrier. Of course, no satellite-direct-to-phone service is available in the U.S. yet, so the financial terms of such offerings will not be known for some time.