SoftBank continued its fascination with flying base stations, conducting yet more tests in a bid to prove the concept viable for supporting direct-to-device coverage.

The Japanese giant teamed up with the country’s National Institute of Polar Research and Hitotsubashi University to conduct ground-based tracking and laser ranging. Blimp-like aircraft, formally known as high-altitude platform stations (HAPS), took to the skies while engineers on the ground used portable lasers to reflect signals off them.

The tests acted as demonstrations of how optical wireless communications equipment works when installed on a HAPS. SoftBank contends that laser ranging requires highly precise tracking to direct beams, but engineers were able to continuously receive reflected signals back down.

“In the future, this technology will enable a HAPS to be tracked from the ground or satellites as its position changes dynamically while remaining aloft,” a SoftBank statement following the tests reads.

SoftBank’s growing obsession with HAPS and flying base stations forms a part of its wider Ubiquitous Transformation (UTX) strategy. The carrier is looking beyond traditional terrestrial means to connect users, including via low Earth orbit (LEO) satellite connections. It works alongside Starlink, but SoftBank said it plans to demonstrate “optical wireless communications between space and the ground” later this year.

Its HAPS efforts have seen it invest in U.S.-based Sceye, which develops the blimp-esque aircraft. One such design was used in its latest round of tests, with another HAPS system recently floating from the skies of Roswell, New Mexico, to Japan in a bid to simulate smartphone connectivity in the event of a major disaster.

Following its latest round of tests, SoftBank said in a statement: “By analyzing the data obtained in this demonstration, including the attenuation of light as it propagates through the atmosphere between the ground and the stratosphere, the team can now examine in detail the requirements for optical wireless communication equipment on HAPS and how such equipment should be installed.”

SoftBank is targeting commercial HAPS operations by next year at the earliest.

“This achievement represents an important step toward realizing future optical wireless communications between satellites, HAPS and the ground.”