Social networking leviathan Facebook wants Australia to leave open the option of so-called high altitude platform stations (HAPS) employing the 28GHz spectrum band used locally for satellite services.
Facebook has long expressed an interest in the potential of solar-powered aerial platforms to deliver Internet connectivity in regional and remote areas.
In 2015 it revealed details of ‘Aquila’: An effort, begun in 2014, to build a solar-powered, unmanned aircraft that could deliver connectivity over a 50-kilometre radius for up to 90 days without needing to land.
The signal from Aquila would be received by small towers or dishes and then converted to a Wi-Fi or LTE network. The Facebook-built Aquila had an airspan greater than a Boeing 737 and would fly at between 60,000 and 90,000 feet. The company conducted two full-scale test flights of the aircraft.
In November 2017 the company revealed it was working with Airbus “to advance spectrum and aviation policy and continue to demonstrate the viability of HAPS systems for providing broadband connectivity”.
In June 2018, however, it revealed that although it was still interested in the potential of HAPS, it had cancelled the Aquila project.
“Going forward, we’ll continue to work with partners like Airbus on HAPS connectivity generally, and on the other technologies needed to make this system work, like flight control computers and high-density batteries,” a blog entry by Facebook’s Yael Maguire said.
Earlier this year a report from Netzpolitik.org revealed that Facebook and Airbus had sought permission to conduct HAPS tests in Australia using the latter’s Zephyr drone.
Test flights were scheduled to be conducted late last year in Western Australia following meetings between the companies and the Civil Aviation Safety Authority (CASA), though Netzpolitik said it wasn’t clear whether the trials went ahead. Facebook has been approached for comment.
The Australian Communications and Media Authority (ACMA), which oversees the licensing of spectrum, is in the process of developing plans for the future of the 28GHz band.
The US, South Korea, Canada, Japan, and Singapore have all earmarked at least some spectrum in the band for use in 5G services. Telstra and Optus have both said that ACMA should leave that as a potential option in Australia.
Currently the regulator is contemplating a hybrid use model that would exclude 5G mobile broadband but allow parts of the band to be used by satellite services as well as some fixed wireless and point-to-point wireless services.
However, access to the 28GHz band for HAPS “is a critical enabler for short-term HAPS deployment, as it represents the main resource for worldwide HAPS downlink transmissions,” Facebook’s director of engineering, spectrum and standards, Michael Tseytlin, has argued in a submission to an ACMA consultation.
In 23 countries the 27.9-28.2 GHz frequency range has been identified for HAPS-to-ground communication under No 5.537A of the ITU-R Radio Regulations. Australia is currently not party to No 5.537A.
The World Radiocommunication Conference 2019 (WRC-19) will be held on October-November this year and agenda item 1.14 will consider “appropriate regulatory actions for high-altitude platform stations (HAPS), within existing fixed-service allocations,” based on an WRC-15 resolution that contemplated 27.9-28.2GHz for HAPS downlink paired with 31.0-31.3GHz for uplink.
“This potential change in the Radio Regulations will facilitate the demand for spectrum access in this band by HAPS operators at the national level, particularly in countries -like Australia- where geographical characteristics are most suited for deployment of stratospheric broadband platforms,” Tseytlin argued.
The ACMA has noted that while using 28GHz for HAPS has been suggested, it is not considering the option at the moment. “Moving forward the ACMA will continue to monitor international and domestic developments for HAPS, including the outcomes of WRC-19, in the 28 GHz and other bands,” the ACMA said in its 28GHz options paper.
“Consideration of possible arrangements for HAPS will be progressed under a separate consultation process as demand and spectrum options become more certain.”
“While welcoming Australia’s initiative to progress arrangements for HAPS in this band under a separate consultation process as demand and spectrum options become more certain, we invite to adopt planning alternatives that safeguard spectrum capacity for the Fixed Service under which HAPS will operate,” Tseytlin wrote in his submission.