Alphabet X is delivering high-speed internet via beams of light through the air transmitting data across the Congo River.

Project Taara is one of Alphabet X’s (formerly Google X) so-called “moonshot” ideas. The technology, known as Free Space Optical Communications, grew out of experiments the team had previously used to beam lasers between balloons in Project Loon, which was shut down by Alphabet in February because it was no longer seen as commercially viable.

The latest experiment means that a “particularly stubborn connectivity gap” between the two African cities – Brazzaville of the Republic of the Congo and Kinshasa in the Democratic Republic of Congo – has been stated to be filled. Whilst, the cities only lie three miles apart in distance, connecting them is tricky because traditional broadband cable has to be routed around the river. This increases the broadband prices by around five times.

Image Source: Alphabet X

The hardware includes pointing and tracking beacons that beam light to each other across distance

The wireless optical communications (WOC) system provided nearly 700 terabytes of data over 20 days with a near perfect, 99.9% availability.

“While we don’t expect to see perfect reliability in all kinds of weather and conditions in future, we’re confident Taara’s links will continue to deliver similar performance and will play a key role in bringing fast, more affordable connectivity to the 17 million people living in these cities,” it said in Alphabet X’s blog.

It is the latest iteration of the project, which has been in development for three years. X is working with Econet Group and Liquid Telecom to bring high-speed internet to sub-Saharan Africa and has begun a commercial rollout in Kenya.

The system uses very narrow, invisible beams of light to deliver high speeds, similar to the way traditional fibre in the ground uses light to carry data but without the cable casing. It is not perfect and the team admits it will not offer full reliability in challenging conditions, such as fog, haze or when birds fly in front of the signal.

As said above, the system does not work well in conditions that may interrupt the beam of light But this has been improved by adjusting the level of laser power being transmitted, relying on mirrors, lights, software and hardware to move the beam to exactly where it needs to be, which works a bit like a telescope. The team have also found ways to reduce errors due to interruptions, such as birds flying through the link.

“While foggy places may never be an ideal spot to use WOC, there are many, many places around the world with ideal weather conditions for Taara’s links,” the blog read.

The technology has also been trialled in Kenya, India, the US and Mexico.