A project from Google parent company Alphabet is now delivering high-speed internet in Africa. But instead of fiber optic cabling, it’s using light pulses to beam broadband through the air.
The technology works by shedding the need to transmit the internet through underground, expensive cabling. Instead, Alphabet’s team developed a terminal fitted with a large lens that can beam the light pulses carrying the broadband to another terminal.
The same terminals can sit on a cell tower, and then beam and receive the internet data as far as 20 kilometers away. The only requirement is that the terminals maintain a clear line of sight between them.
The effort, dubbed Project Taara, recently applied the technology to expanding broadband to two cities in the Congo that are separated by a river.
“Brazzaville and Kinshasa are only 4.8 kilometers apart—yet connectivity is five times more expensive in Kinshasa because the fiber connection has to travel more than 400 kms to route around the river,” Baris Erkmen, Taara’s director for engineering, wrote in a blog post.
Indeed, a challenge with bringing high-speed internet to everyone is that fiber optic cabling can be expensive or impossible to install, given the terrain. However, Alphabet’s team was able to circumvent the river by installing the Project Taara terminals on towers located in both cities.
“After installing Taara’s links to beam connectivity over the river, Taara’s link served nearly 700 TB of data—the equivalent of watching a FIFA World Cup match in HD 270,000 times—in 20 days with 99.9% availability,” Erkmen said.
The technology was borne out of a now-shuttered Alphabet subsidiary called Project Loon, which involved transmitting high-speed internet to users via high-altitude balloons. One research effort at Loon used wireless optical communication to help one balloon communicate with another.
The team at Project Taara has since been refining the technology for use closer to the ground. It currently can deliver broadband speeds of up to 20Gbps. However, one challenge facing the technology is the need to maintain a clear line of sight from one Taara terminal to the next. As a result, birds flying through the beams or even a monkey shaking a terminal can disrupt the internet connection, Erkmen said.
In response, the team has been building automated systems to help ensure the terminals can maintain a steady connection. “These techniques, combined with better pointing and tracking capabilities, has meant that when Taara’s beam has been affected by haze, light rain, or birds (or a curious monkey) we’ve not seen any service interruptions,” Erkmen said.
Still, the technology is ill-suited for certain areas of the world that have constant fog, such as San Francisco. Nevertheless, the team has identified numerous areas of the world where it expects Project Taara can help supply consistent high-speed broadband to local users.
“Being able to deliver high-speed internet (up to 20Gbps) most of the time is a vastly better option than having millions of people miss out on the benefits of connectivity because the economics of laying hundreds of kilometers of cable in the ground simply don’t stack up,” Erkmen added.
The technology could be a godsend for rural internet users stuck with slow broadband. But it remains unclear when Project Taara might see wider use. The Project Taara website merely says: “The team is in conversation with Telcos, ISPs and governments around the world about the potential for wireless optical communication technology.”
