Facebook is working on the first-ever transatlantic, 24-fiber-pair subsea cable system that will connect Europe and the United States with a capacity of half a petabit per second — roughly half a million gigabits. The company also announced its Terragraph technology, which creates an mmWave mesh to solve the problem of last-mile connectivity.
The company has not revealed any more details on when the undersea cable will be operational.
However, Facebook’s connectivity team did share more details on its 2Africa Pearls undersea cable, which was announced earlier this year. The Africa cable project cable will connect Africa to Asia and Europe landing in 46 cities in 33 countries.
“We have even designed floating power stations that sit in the middle of the ocean, harnessing the power of the sun and the waves, delivering it to the cables in the ocean floor, allowing us to boost their capacity,” Facebook CTO Mike Schroepfer said during a press briefing.
“We are building more than 150,000 km of subsea cables with our partners, alongside new technologies that will dramatically improve the capacity and performance of those cables. This will have a major impact on underserved regions of the world, notably in Africa, where our work is set to triple, triple the amount of internet bandwidth, reaching the continent,” Dan Rabinovitsj, Vice-President, Facebook Connectivity explained.
The company has built a predictive model to help them forecast where subsea cable routes need to be built to ensure high network availability. “Each route is examined for localised hazards from fishing and undersea volcanoes, etc,” Cynthia Perret, Program Manager – Submarine Cables at Facebook explained.
Perret pointed out that very often the capacity of an undersea cable is limited by the amount of electricity it can receive, via the booster boxes and this typically comes from onshore. “We are exploring a sustainable way of doing this using a combination of wave energy converters and solar panels. The aim is to continuously generate up to 25 kilowatts of power to supply two subsea cables at various points in the middle of the ocean,” she stressed, though the technology is still being tested.
Facebook’s Terragraph technology, meanwhile, wants to solve the problem of last-mile connectivity, especially in areas where laying down fiber cable to each home might not be possible. It is already in use in Anchorage, Alaska, and Perth, Australia. Terragraph is being used in Alaska by Alaska Communications, where deploying fiber is a lot more challenging given the environmental conditions.
It is a transmitter box mounted on street signs and lamp posts and delivers multi-gigabit performance wirelessly. Yael Maguire VP, Engineering at Facebook explained Terragraph was like “extending fiber in the air,” and it builds upon “existing fiber points by extending their capacity.”
The Terragraph boxes act as a mesh network of sorts and Facebook says it has worked with a number of partners, including Qualcomm to build this. It uses mmWave technology at 60 Hz spectrum. Facebook also stress-tested this in its own Menlo Park headquarters before rolling out the technology prototype.
“We licensed Terragraph for free to manufacturers and five of them are now selling their Terragraph enabled products. These partners have shipped more than 30,000 Terragraph units to more than 100 service providers,” Maguire explained.
Facebook says Terragraph is designed to work in extreme conditions, whether it’s rain or snow or wind or heat. It can also withstand temperatures as low as minus 20 degrees C and as high as 55 degrees. It is being touted as a multipoint solution, which can beam the network to multiple points, even when there are minor obstructions, and help build reliable and high-speed connectivity for nearby homes and businesses.
Facebook also wants to tackle the problem of laying down the fiber cables in a faster way. The solution is a robot called Bombyx that moves along existing power lines and installs fiber optic cables directly onto them. Bombyx can help bring down the cost of deploying fiber. The company has worked with top plastics experts to develop a special jacket material for the fiber to help it survive the high temperatures of the power line.
It also claims that their fiber cable is 10 times lighter and smaller than a normal aerial fiber cable, and three times smaller than the cable used in traditional deployment.
As for the Bombyx, it has been designed to withstand line voltage just between 10,000- 35,000 volts. “We had to design special circuits and enclosures to handle this,” explained Karthik Yogeeswaran, Wireless Systems Engineer at Facebook. He pointed out the robot also has to overcome obstacles on the powerlines and sort of walk the tightrope on these as it lays down the fiber.
“Our solution here was to use thruster fans, similar to those used in drones. The control algorithm to keep the robot stable turned out to be a much harder problem than we anticipated. The robot hangs on a curve, so the front and back experience different sway conditions, making this even harder. Each movement induces vibrations and changes to the center of gravity of the robot. The control algorithm needs to compensate by adjusting the speed of all the thrusters to keep the robot vertical while simultaneously preventing the cable from swaying,” he pointed out.
In order to overcome obstacles, the robot will use a 3D map of the world, which is generated from an onboard stereo camera. Bombyx is still in the prototype phase for now, though Facebook is starting discussions with a handful of electric utility companies.