Japan's Space RAN Venture - Combining Land, Air, and Space

NTT, along with its mobile unit NTT DOCOMO, has joined forces with Airbus and satcom operator SKY Perfect JSAT, to work on Space RAN.

Under the same, the consortium will look to explore the potential of high-altitude platform stations (HAPS), as a part of a "future space-based wireless connectivity ecosystem". The ecosystem will converge the connectivity capacities of geostationary satellites, LEO satellites, HAPS vehicles - drones, balloons - and terrestrial networks.

Space RAN - The Latest in Radio Technology

In this current setup, NTT and DOCOMO will provide the terrestrial networks, satellites will come from SKY Perfect JSAT, and the HAPS element will come from Airbus. Incidentally, Airbus has developed a solar-powered UAS called Zephyr. Zephyr will fly in the stratosphere, 20 kilometers above the earth's surface, and form the HAPS element of the Space RAN.

For now, the companies are exploring their options. The parties involved will "test HAPS connectivity, identify practical applications, develop required technologies, and ultimately launch space-based wireless broadband services". This convergence, hopefully, will deliver connectivity across the planet, and even above it. Given it's called Space RAN, one would hope so, too.

The partners have said that they will test base station backhaul, how different spectrum bands perform, and the technology required for linking HAPS with satellites and ground base stations. Along with this, the partners will build a cooperative system that will tie NTN technology, satellites, and HAPS together.

Incidentally, the tests seem to be going smoothly; NTT DOCOMO and Airbus have successfully tested the Zephyr platform. The tests showed that HAPS-based services operate well enough on the 2 GHz spectrum.

Is HAPS Still Good Enough?

While the Space RAN alliance over here has discovered some use for HAPS vehicles, it has a rather blemished past. Earlier, Facebook and Google have tried and failed at using HAPS devices for connectivity purposes.

Facebook tried with its development project called Aquila. However, that one died a quiet death in 2018.

Google, though, struggled the longest with it. Google's parent company, Alphabet, sank a lot of money, time, and manpower in Loon, a fleet of helium balloons floating in the stratosphere. However, even Google stopped struggling with it in January 2021; by then, SoftBank had also sunk $125 million in the project.

Their experience, though, might not go to waste after all.

5G, 6G, and Beyond, with Space RAN

Interestingly, SoftBank also took about 200 HAPS patents from Loon in September last year.

The Japanese company had noted, "with these patents, SoftBank and its subsidiary, HAPSMobile Inc., will collectively own approximately 500 HAPS-related patents, including patents pending, further establishing their position as intellectual property (IP) leaders in the HAPS industry. The patents are related to network technologies, services, operations and aircraft for HAPS".

The Space RAN alliance have their eyes on the future, that much is clear. NTT has called these developments an important part of 5G, and a part of 6G as well. With SoftBank's HAPS stake, it looks like the alliance might do well with it on board as well. Also, another Japanese telco, KDDI, is a member of the HAPS alliance, along with Airbus, NTT DOCOMO, and SoftBank. Therefore, Japan's Space RAN venture seems like it might actually work.