Airbus, Nippon Telegraph and Telephone Corporation (NTT), NTT Docomo and SKY Perfect JSAT have jointly announced that they have begun studying the feasibility of collaborating on future high-altitude platform station- (Haps-) based connectivity services as part of a future space-based wireless connectivity ecosystem.

Launched with the signing of a memorandum of understanding (MoU) on January 17, the study aims to identify the early deployment requirements of a Haps-based network.

The collaboration will investigate the use of the Airbus Zephyr – a fixed-wing, solar-powered, stratospheric unmanned aerial system – and the wireless communication networks of NTT, Docomo and SKY Perfect JSAT to test Haps connectivity, identify practical applications, develop required technologies and, ultimately, launch space-based wireless broadband services.

In the global push to further advance fifth-generation (5G) connectivity and eventually introduce sixth-generation (6G) connectivity, initiatives are under way to expand coverage worldwide, including in the oceans and in the air, as well as remote and hard to reach areas.

Such initiatives will include Haps, which fly in the stratosphere about 20 km above the earth, and nonterrestrial network (NTN) technologies using geostationary-orbit satellites and low Earth-orbit satellites.

Haps networks are deemed to be a relatively easy solution for air and sea connectivity and an effective platform for deploying disaster countermeasures. They also have many industrial applications.

The provision of space-based radio access network services using NTN technologies, collectively called Space radio access network, is expected to support worldwide mobile communications with ultrawide coverage and improved disaster resistance, as well enhanced 5G and 6G connectivity.

Moreover, Haps platforms can also interconnect to the nearest terrestrial network gateway and extend the reach of existing mobile services directly to end-user devices, providing service options including rural, emergency and maritime connectivity.

With the signing of the MoU, the four companies will discuss and identify possible future developments necessary to unlock future Haps-based connectivity services, lobby for standardisation and institutionalisation of Haps operations, and explore business models for commercialising Haps services.

Specific themes will include the applicability of Haps for mobile connectivity on the ground and base station backhaul, the performance of various frequency bands in Haps systems, the technological considerations for linking Haps with satellites and ground base stations, and the establishment of a cooperative system to test a network combining NTN technology, satellites and Haps.

As separately announced on November 15, 2021, Docomo and Airbus successfully conducted a propagation test between the ground and a Zephyr S Haps aircraft in the stratosphere, demonstrating the possibility of providing stable communication with such a configuration.