Petabit-class networks will support more than 100-times the capacity of existing networks, according to scientists who have just demonstrated an optical switching rig designed to handle the significant amounts of data that would pour through future petabit cables. One petabit is equal to a thousand terabits, or a million gigabits.
Researchers at the National Institute of Information and Communications Technology (NICT) in Japan routed signals with capacities ranging from 10 terabits per second to 1 petabit per second through their node. Those kinds of capacities, which could send 8K resolution video to 10 million people simultaneously, are going to be needed for future broadband video streaming and Internet of Things at scale, researchers believe. In-data-center applications and backhaul could benefit.
“Petabit-class transmission requires petabit-class switching technologies to manage and reliably direct large amounts of data through complex networks, NICT said in a press release. “Up to now, such technologies have been beyond reach, because the existing approaches are limited by complexity and, or performance.”
In this case, NICT used “large-scale” spatial optical switching with spatial-division multiplexing to build its node. Three types of multicore fibers were incorporated, all with different capacities, in order to represent different scenarios, like metropolitan or regional networks. MEMS technology, too, was incorporated. That’s equipment built on micro-electro-mechanical systems, or a kind of merging of micrometer-measured, nanoscale electronics devices with moving parts.
NICT says that within its testing, it was able to not only perform the one petabit optical switching, but also was able to run a redundant configuration at one petabit per second. That’s to support network failures such as breaks in the fiber. It used 22-core fiber for both of those scenarios.
Additionally, NICT branched the one petabit signals into other multicore optical fibers with miscellaneous capacities. It used 22-Core Fiber, 7-Core Fiber and 3-Mode Fiber. Finally, running at a slower 10 terabits per second, it managed that lower capacity signal within the capacious one petabit per second network— NICT says that that kind of application would be most suitable for regional networks, whereas the other scenarios apply best to metro networks.
Actual, straight, petabit-class transmissions over fiber have been achieved before. In 2015 NICT was involved in the successful testing of a 2.15 petabit per second signal over a single 22-core fiber. Then, it said, in a press release, that it was making “progress to the practical realization of an over one petabit per second optical fiber.” (Typical real-world limits, right now, include 26.2 terabits, in an experiment, over a transatlantic cable, and an 800 gigabit fiber data center solution Ciena is pitching.)
In 2018 NICT said, in another news release, that it had tested a petabit transmission over thinner 4-core, 3-mode fiber with a diameter of 0.16 mm (0.006 inches): There’s an advantage to getting the cladding diameter as small as possible—smaller diameter fiber has less propensity to mechanical stress damage, such as bending or pulling, NICT explains. It can also be connected less problematically if it has a similar diameter to existing fiber cables, already run.
“This is a major step forward towards practical petabit-class backbone networks,” NICT says of its current 22-core fiber, one petabit per second switch capacity experiments. These will end up being “backbone optical networks capable of supporting the increasing requirements of internet services,” it says.
