Alphabet’s subsidiary Loon and SoftBank’s subsidiary HAPS Mobile succeeded in a joint experiment to territorialize the ground from an unmanned electric plane in the stratosphere.
This experiment was conducted on September 21 (local time) in New Mexico, USA. The Sunglider, an electric plane developed by HAPS Mobile over three years, was equipped with a 30 kg radio and flew autonomously in the stratosphere for more than 5 hours while developing with solar panels. At this time, LTE communication using MIMO was performed.
As a result, land-based commercial smartphones succeeded in making high-quality, low-latency video calls over LTE through the radio mounted on the same plane. It has succeeded in terrestrial LTE using airplanes flying in the stratosphere as well as indoors.
The frequency used for the experiment is the LTE band 28 700MHz band between the smartphone and the airplane, and the 70~80GHz range between the airplane and the ground gateway. In addition, basic radio wave measurement for international standardization of some of the frequency bands that need to be reviewed for stratospheric communication networks was also carried out. HAPS Mobile and Loon will continue to cooperate to propose standardization to the standardization organizations 3GPP and ITU.
In the midst of rapid mobile network maintenance such as LTE and 5G, to use land base stations in mountainous areas, at sea, and in developing countries, localization of the last one mile is becoming a challenge. Therefore, the concept of deploying high-speed communication directly from the stratosphere and space to the ground rather than having a terrestrial base station is attracting attention. Related information can be found here.