Comcast staked a claim as the first U.S. operator to trial hollow core fiber technology, eyeing latency and speed gains which could enable new use cases and support its rollouts of 10G capabilities.
“When you look at the opportunities for terrestrial distribution and the opportunities for continued innovation in terms of delivery, I think that this is a great example of what comes next,” Comcast Cable's SVP of next generation access networks Elad Nafshi told Fierce.
Just as the name suggests, hollow core fiber cables have an air-filled central channel surrounded by a ring of glass strands such that a cross section looks rather like honeycomb with an empty hole in the middle. The idea behind this arrangement is that light travels 50% faster through air than over glass, meaning such cabling can deliver better performance and lower latency.
In a trial conducted alongside hollow core fiber vendor Lumenisity, Comcast deployed a 40-kilometer (nearly 25-mile) hybrid hollow core and traditional fiber link over which it successfully tested upstream and downstream transmissions. It was able to produce traffic rates ranging from 10 Gbps to 400 Gbps simultaneously on a single strand of hollow core fiber. Nafshi added the operator was also able to demonstrate hollow core fiber is backwards compatible.
So why is a cable operator like Comcast interested in next-generation fiber? Nafshi noted the technology has the potential to deliver data 150% faster with up to 33% lower latency, meaning it could make a big impact whether deployed for core or access.
“While our edge network is predominantly coaxial, we still have a very large fiber network throughout the U.S.,” he explained. “Having this as one of the options certainly creates some potentially very interesting use cases for us.” That includes applications across a range of verticals like financial services, telemedicine and augmented and virtual reality, or any other use case which is latency sensitive or data intensive.
“We want to be on the bleeding edge of network delivery and we think that hollow core is one of those technologies that has the potential to really create something very unique and very special,” Nafshi concluded. In terms of what comes next on this front, Nafshi said Comcast has "a lot of rigorous testing" ahead of it in the weeks and months to come.
While Comcast believes it is the first in the U.S. to test hollow core fiber and its 40 km deployment to be the longest to date, it’s not alone in trialing the technology. U.K. operator BT revealed it was testing hollow core fiber in June 2021.