A groundbreaking call has taken place between Texas and Japan that could ultimately help pave the way for a globally accessible space-based mobile network. AST SpaceMobile – a Texas-based satellite manufacturer – announced Tuesday that it had successfully routed an audio call between two standard smartphones directly through its BlueWalker 3 (BW3) satellite in low Earth orbit, a breakthrough that could improve global cellular connectivity in remote regions without access to cell towers.
AST SpaceMobile claims this is “the first time anyone has ever achieved a direct voice connection from space using everyday mobile devices.” The call was made from an unmodified Samsung Galaxy S22 in Midland, Texas, using AT&T’s cellular spectrum and connected to an iPhone used by Japanese tech giant Rakuten. Engineers from AT&T, Rakuten and British telecommunications company Vodafone helped with the test.
The BW3 satellite is powerful enough to pick up GSM signals from over 1000 miles away
Usually, an everyday smartphone should not be able to communicate directly with satellites in space as they use different spectrums, instead phones need to connect to nearby cell towers. AST SpaceMobile got around this in a few ways, such as purposefully designing its network architecture to keep the 3GPP (3rd Generation Partnership Project) standard used by terrestrial mobile networks – that and the BW3 satellite is an absolute beast: at 693 square feet (just over 64 square meters), it’s the largest commercial communications array ever deployed to low Earth orbit, capable of picking up cell phone signals from over 1,000 miles away thanks to its 100,000 individual antenna elements.
The engineering effort involved here meant that the phones connected to BW3 required no hardware or software changes – no fancy apps required, just the default Samsung dialer. The companies involved have not disclosed performance details, but an AT&T spokesperson confirmed that The edge that the first test call has been made over 2G and that the next phases of testing will include LTE, 4G and 5G.
The main goal of direct cell-to-satellite communications is to improve global cellular access in remote regions without infrastructure such as cell towers. This includes rural areas of the US struggling to even establish a 3G wireless connection let alone 5G. In addition to AT&T, Rakuten and Vodafone, AST SpaceMobile has agreements with mobile network providers such as Bell Canada, Telefónica and Orange, which together have approximately 2 billion subscribers. We currently have no information on how these providers will be able to incorporate direct satellite connectivity into their existing services or when such a utility could come to general consumers.
Other providers have formed similar partnerships to expand rural broadband access using satellites. In 2021, Verizon announced it is partnering with Amazon to add “cellular backhaul solutions” to the e-commerce giant’s Project Kuiper system, which is expected to be deployed in 2024. Elsewhere, smartphone services have developed message-based satellite routing solutions, such as Apple’s Emergency SOS feature for the iPhone 14.