BT Group and Stratospheric Platforms are looking to provide 4G LTE and 5G connectivity to remote areas of the United Kingdom using new antenna technology riding on high-altitude platform station (HAPS) aircrafts. Trials are being conducted in BT’s research headquarters in Adastral Park.

The phased-array antenna will use 500 individually steerable beams with a 140-km or 15,000 square-km radius, which the companies tout is the equivalent to the average footprint of 450 terrestrial towers.

BT Group Managing Director of Research and Networks Strategy Tim Whitley explained to SDxCentral via email that testing and development will take place throughout this year and 2024, and flight trials are anticipated to begin in 2025 – with entry into service in 2026.

The project faces a number of challenges, according to Whitley, including “generating sufficient on-board power for the array antenna and [keeping] the aircraft in position in all wind conditions,” cooling the electronics once it enters the stratosphere, creation of the modular antenna with “the capability to create a large number of reconfigurable beams to enable sufficient capacity equivalent to terrestrial network service levels,” and maintaining a stationary beam pattern from the ground as the aircraft circles in a holding pattern.

In the release, Whitley claims the project will further the groups 4G LTE and 5G footprint in the U.K. and connect unserved rural markets. HAPS aircrafts are a developing means to address the rural digital divide alongside other nascent methods like using low-Earth orbit (LEO) satellites.

Whitley did say the HAPS aircraft may be “part of the solution” in closing the digital divide, though it “must be viewed as one of a range of connectivity options that will need to be rolled out to rural areas.”

“Fixed services are part of the solution and in tandem to exploring mobile connectivity solutions for those in hard-to-reach areas, we are building our own gigabit capable network. Despite this, there will still be a gap in providing connectivity to the ‘hardest to reach’ [areas], which will require government support,” he added.

The partnership also hopes to use the solution as a fallback for terrestrial network failures, emergency scenarios, and as remote monitoring in different industrial or agricultural applications.

Photo: Conceptual Image of a HAPS Aircraft. Source: BT Group