Comcast Becomes First ISP in the United States to Deploy Advanced Hollowcore Fiber with Faster Speed, Lower Latency

PHILADELPHIA, PA: Comcast, the nation’s largest gig-speed Internet provider, today announced what is believed to be the first-ever end-to-end deployment of advanced “hollowcore” fiber optics in the world by an Internet provider.

Hollowcore fibers deliver significantly lower latency than traditional fibers and over time will provide critical performance attributes. These fibers will help power Comcast’s network and support the delivery of multigigabit speeds through 10G.

Unlike traditional fibers, in which laser light travels over a solid glass core, hollowcore fibers are empty inside with air-filled channels. Since light travels nearly 50 percent faster through air than glass, data travels about 150 percent faster with up to 33 percent lower latency through hollowcore fiber compared to traditional fiber. The faster speed of light can be used to double the reach for latency critical applications or can speed up the transaction rates by around 47 percent. For the deployment announced today, Comcast worked with hollowcore fiber cable solutions provider, Lumenisity.

“Hollowcore fiber is a leap forward in how we deliver ultra-fast, ultra-low latency and ultra-reliable services to customers,” said Elad Nafshi, EVP & Chief Network Officer at Comcast Cable.

"As we continue to develop and deploy technology to deliver 10G, multigigabit performance to tens of millions of homes, hollowcore fiber will help to ensure that the network powering those experiences is among the most advanced and highest performing in the world," said Elad Nafshi. 

Comcast connected two locations in Philadelphia, which enables network engineers to continue to test and observe the performance and physical compatibility of hollowcore fiber in a real-world deployment. This 40-kilometer hybrid deployment of hollowcore and traditional fiber is believed to be the longest in the world by an Internet provider. Comcast successfully tested bidirectional transmission (upstream and downstream traffic traveling on a single fiber), used coherent and direct-detect systems (allowing for forward and backward technology compatibility), and produced traffic rates ranging from 10 gigabits per second (Gbps) to 400 Gbps all simultaneously on a single strand of hollowcore fiber.

“We are proud to be working with Comcast on the next generation hollowcore fiber, which we believe unlocks exciting new potential for connectivity around the world,” said David Parker, Executive Chairman of Lumenisity.

Hollowcore fiber will help to power the next generation of ultra-low latency technologies to support network virtualization, telemedicine, augmented and virtual reality, and other emerging services. Moving forward, Comcast is exploring opportunities to strategically deploy hollowcore fiber in select core- and access-network deployments. From 2017 to 2021, Comcast added more than 50,000 new route miles of fiber to its network and is actively building more fiber into cities and towns across the United States.

Comcast’s ongoing work to expand and evolve its fiber deployments – including this groundbreaking step forward with hollowcore fiber – helps to power Comcast’s ongoing 10G evolution, which will deliver reliable multigigabit upload and download speeds over the connections already installed in tens of millions of homes and businesses.