US satellite player AST SpaceMobile made a two-way satellite call to Rakuten Group using unmodified smartphones and AT&T spectrum, marking what it claimed was an industry first.

The first voice call was made from the US state of Texas to Rakuten in Japan with Samsung Galaxy S22 smartphones connected to AST SpaceMobile’s BlueWalker 3 (BW3) test satellite.

AST SpaceMobile stated engineers from Vodafone Group, Rakuten and AT&T participated in the preparation and testing of the voice calls with the satellite.

The satellite company has long-touted its BW3 satellite deployment, which it claimed is the largest-ever commercial communications array deployed in low Earth orbit.

AST SpaceMobile stated the call with Rakuten and AT&T was the first step towards providing space-based 2G, 3G, 4G and 5G mobile broadband globally to standard devices.

Abel Avellan, AST SpaceMobile CEO, hailed the trial as the company’s most significant milestone to date.

In addition to test calls, AST SpaceMobile engineers also conducted initial compatibility tests on a range of smartphones and devices, which exchanged SIM and network information directly with the satellite.

Further testing and measurements on the smartphone uplink and downlink signal strength confirmed AST SpaceMobile’s ability to provide mobile broadband data rates and 4G/5G waveforms.

AST SpaceMobile also has partnerships with operators including Bell Canada, MTN Group, Orange, Telefonica, Etisalat and Indosat Ooredoo Hutchison.

Competitors including Lynk Global, SpaceX, Amazon and OneWeb are targeting the same satellite-based opportunities.