SoftBank Corp pushed on towards an ambition of delivering 5G from a High Altitude Platform Station (HAPS), conducting a field trial of a payload able to provide stable connectivity over a wide-area.

Its latest test was for a six-cell communications payload intended to deliver 5G wireless communications from the stratosphere to the ground.

The company noted it “integrates equipment for a service link,” which connects the HAPS platform to mobile devices, with a feeder link connecting it to a “ground gateway” which provides the link to a base station.

A small white twin-propeller plane with the registration JA8229 sits on a concrete runway. The aircraft has a red stripe along its side, large windows, and a mountainous landscape in the background under a cloudy sky.

SoftBank’s test was conducted in Tokyo and used a light aircraft (pictured) flying at an altitude of 3,000 metres.

With the addition of “footprint fixation technology” the company noted the trial “proved its newly developed payload can provide wide-area and stable communication services from the sky”.

It reported a mobile device on the ground recorded an average downlink speed of 33 Mb/s at a location 15km from the centre of the aircraft’s circling path.

SoftBank noted the result “confirmed that end-to-end 5G communication via the service link and feeder link is possible even at the edge of the coverage area”.

Its development is the latest towards a goal of providing multicell payloads for HAPS platforms capable of providing coverage across a diameter of up to 200km.  

The company plans to use the results of the trial to work on further improvements to the payload with the aim of capacity improvements in future commercial services.