CommsUpdate: Japan’s fourth mobile network operator (MNO) Rakuten Mobile and US-based satellite designer and manufacturer AST SpaceMobile have claimed a world ‘first’ with the successful completion of a two-way voice call with standard mobile phones using the BlueWalker 3 (BW3) satellite.
In a press release, the companies confirmed that the call was made from the Midland, Texas area to Rakuten Mobile in Japan over AT&T spectrum on 21 April 2023.
“This is the first time anyone has ever achieved a direct voice connection from space to everyday cellular devices, demonstrating a significant advancement in AST SpaceMobile’s mission to provide broadband services to the nearly 50% of the global population who remain unconnected,” the statement read.
AST SpaceMobile heralds proof of concept call
AST SpaceMobile said the test calls certified both its patented system and architecture and the capabilities of the BW3 satellite, which the gear maker claims to be “the largest-ever commercial communications array deployed in low Earth orbit [LEO].”
The BW3 satellite is essentially a LEO cellular base station that can carry voice, video, data and internet access via 2G, 4G and 5G bands. This is why it can connect to regular mobile phones, as opposed to LEO systems like Iridium that require specialized terminals with enough RF and battery power to connect to the satellites.
Because smartphones operate at far lower powers than satellite phones, AST SpaceMobile’s idea is to launch LEOsats with larger arrays of almost 700 square feet.
BW3 was launched in September 2022 as a test satellite for the network. AST SpaceMobile plans to launch a fleet of 20 LEO satellites orbiting earth’s equatorial region starting later this year.
On the road to global 5G
The release went on to note that the test call “is an important step to providing space-based 2G, 3G, 4G LTE and 5G cellular broadband globally.”
AST SpaceMobile added that “engineers from Rakuten, Vodafone and AT&T participated in the preparation and testing of the first voice calls with BW3.”
Vodafone and Rakuten became investors in AST SpaceMobile in 2020.