Texas and Japan have made a groundbreaking call that could help pave the way for a global space-based cell network. AST SpaceMobile, a Texas satellite manufacturer announced Tuesday it had successfully routed a voice call between two smartphones through its BlueWalker 3 satellite in low earth orbit. This breakthrough could improve global cellular connection in remote areas without access to cell-towers.
AST SpaceMobile says this is the “first time anyone has achieved a direct voice call from space to everyday cellular device.” The phone was made using an unmodified Samsung Galaxy S22 from Midland, Texas. It used mobile spectrum provided by AT&T, and was connected to an iPhone owned by Japanese tech giant Rakuten. The test was conducted by engineers from AT&T and Rakuten as well as Vodafone, a UK-based telecoms company.
Satellite BW3 is powerful enough for it to pick up cell phone signals over 1,000 miles away
Normal smartphones shouldn’t be capable of communicating directly with satellites because they use different frequencies. Instead, phones should connect to nearby towers. AST SpaceMobile has found ways to overcome this problem, including designing their network architecture to mimic the 3GPP (Third Generation Partnership Project,) standard used by terrestrial cellular systems.Wow, this is huge!
This was due to the technical effort involved. The phones that were connected to BW3 did not require any software or hardware changes. Just the standard Samsung dialer. AT&T confirmed to The Verge, that the first test call was over 2G. The next phases of testing will include LTE and 4G.
Direct cell-to satellite communication’s main objective is to increase global cellular coverage in remote areas that lack infrastructure such as cell towers. Rural areas in the US are also included, as they struggle to get a 3G connection let alone 5G. AST SpaceMobile also has agreements with other mobile carriers networks, including AT&T Rakuten and Vodafone as well as Bell Canada Telefonica and Orange. These networks have a combined 2 billion subscribers. We do not have any information on how or when these carriers could include direct satellite connectivity in their services.
Other carriers have formed similar partnerships in order to increase rural broadband access. In 2021 Verizon announced that it was working with Amazon on “cellular backhaul” solutions for the ecommerce giant’s project Kuiper system. This is expected to begin deployment in 2024. Other smartphone services developed satellite routing solutions based on messages, such as Apple’s emergency SOS for the iPhone 14.