BT eyes HAPS for 4G/5G rural coverage

Sometimes you have to reach for the skies if you want to cover rural areas with mobile connectivity. That’s what BT Group is doing, starting with a trial of new antenna technology developed by Stratospheric Platforms Ltd (SPL).

The tech is designed to be mounted on a High-Altitude Platform Station (HAPS) aircraft, but for this trial, they’re putting it on top of a building at BT’s global R&D headquarters at Adastral Park in the U.K.

The phased array antenna is capable of delivering speeds up to 150 Mbps across areas as wide as 15,000 square kilometers, or an area equivalent to the average footprint of 450 terrestrial masts, through 500 individually steerable beams, according to a press release.

The placement on top of a high building is designed to simulate a high-altitude platform; it will connect to BT’s open RAN testbed on the ground. The test will include multiple user groups and different potential use cases concurrently on the same network.

“We’re delighted to be partnering with SPL to start realizing the huge potential of HAPS aircraft to further strengthen our UK 4G and 5G network technology leadership,” said BT Group Managing Director of Research and Network Strategy Tim Whitley in a statement. “This highly innovative and transformative project has the potential to further enhance our UK 4G and 5G footprint, which is already the largest and most reliable in the UK, to connect unserved rural areas and enable exciting new use cases for private users.”

SPL was founded in Cambridge in 2014 and is supported by Deutsche Telekom. The project with BT is backed with funding from Innovate UK.

Other high-flying attempts to provide coverage from the sky did not fare so well. Facebook had designs to use a fleet of solar-powered aircraft to connect people in remote parts of the world, but the Aquila project was shut down in 2018. Google introduced Project Loon in 2013 and chronicled some successes over the years, but Alphabet pulled the plug in 2021.

The hope is with SPL's technology, BT will be able to not only extend the reach of existing U.K. network infrastructure but also have a fallback for terrestrial networks in the event of a disaster. It also has applications for remote monitoring across various industrial and agricultural use cases, as well as providing energy cost savings.