- AWS has developed its own hollow core fiber to deliver high-bandwidth, low-latency connections across greater distances
- That makes AWS the second hyperscaler - alongside Microsoft - to publicly discuss its use of the technology
- Traditional telecom operators have also toyed with the tech, but supply seems to be an issue
Walking the show floor at AWS re:Invent, Fierce stumbled upon something interesting. No, it wasn’t a robot, or some other gimmicky AI-enabled gizmo. It was a cross section of hollow core fiber. And more specifically, a prototype of the hollow core fiber (HCF) AWS is using to extend its network.
Reps at the AWS booth couldn’t speak on the record and referred Fierce to a recently published company blog that mentioned AWS’ use of the technology to deliver a 30% improvement in latency compared to standard fiber. From there we fell down a truly fascinating rabbit hole.
As a quick refresher, hollow core fiber is exactly what it sounds like: a fiber channel with a hollow, air-filled core. Glass as a medium slows down the speed at which light can travel. By using air, the idea is to enable more bandwidth and/or lower latency, depending on the specific HCF design.
Loss, however, has been an issue for the technology – one which AWS set out to solve.
Why? Well, if hollow core fiber had the same loss characteristics as regular fiber, it could reach 47% farther and still deliver the same latency target, AWS Senior Principal Network Development Engineer Stephen Callaghan said in a presentation at re:Invent 2024.
So, working with several of its vendors, AWS developed a hollow core fiber with loss characteristics similar to those of standard single-mode fiber. Callaghan added the design it created is compatible with its existing fiber tech, meaning it can selectively add hollow core where necessary to extend low-latency, high-bandwidth transport over greater distances.
As might be apparent, this is a big deal in the context of AI and the data center boom.
“For the same latency target using hollow core, we can now go farther. This is almost a 50% increase, meaning we can add these new buildings we previously couldn’t,” Callaghan said in the presentation.
“We can now say to real estate ‘you can have an area that’s nearly double what it was before,’ purely by using this technology,’” he added. Put another way, data center buildings in AWS cloud regions can be farther apart and still meet the company’s technical requirements around latency.
Gaining steam
Telecom operators have led the pack on hollow core fiber, with BT in the U.K. and Comcast in the U.S. trialing the tech as far back as 2021 and 2022, respectively.
More recently, China’s trio of telecom operators have begun testing and deploying hollow core. China Mobile originally trialed the tech with ZTE and vendor YOFC in 2024. That year, YOFC also worked with China Telecom and China Unicom on hollow core fiber, while ZTE trialed the tech with China Telecom.
But interest in hollow core fiber has increasingly cropped up among cloud and data center operators, including Microsoft and Digital Realty. Even Equinix has started talking about it.
Digital Realty last year conducted field tests of the tech with Nokia, wholesale carrier lyntia and OFS in Spain.
Earlier this year, Microsoft, after buying hollow core vendor Lumenisity in 2022, inked a deal with Corning and silica vendor Heraeus Covantics to stand up a “multi-national production supply chain to scale next generation fiber production.”
This latter feels like a turning point given word on the street is that supply is a key factor limiting hollow core fiber’s uptake.