Comcast Deploys Advanced Hollowcore Fiber With Faster Speed, Lower Latency
Comcast 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 Service Provider (ISP). 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 b/sec.
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.”
“The reality is that light travelling through air is about 50% faster than travelling through glass. The data throughput and the latency is greatly improved when you have a hollowcore fiber … The advantage is you can extend your reach at equal performance,” Nafshi said. Hollowcore fiber, like traditional fiber, can be used in the access, metro or core network, and is compatible with legacy fiber.
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.
An illustration of the air-filled channels utilized in hollowcore fiber.
Comcast deployed more than 50,000 new route miles of fiber to its network from 2017 to 2021. The operator isn’t revealing how or when it might commercialize its use of hollowcore fiber, but the operator sees it playing a role for certain apps and use cases, such as telemedicine, AR/VR and network virtualization.
The operator might also use the technology to target new customer segments that are seeking greater throughputs and lower latencies.
From a broader standpoint, hollowfiber could provide a conduit for “10G,” an industry initiative focused on delivering symmetrical 10Gbit/s speeds, low latencies and enhanced security over fiber-to-the-premises (FTTP), hybrid fiber/coax (HFC) and wireless networks.
Citing its 40km connection in Philadelphia, Comcast is billing this as the world’s longest ISP deployment of hollowcore fiber so far.
But Comcast isn’t the only major operator working closely with Lumenisity. Last year, the startup announced BT was trialing its new optical fiber technology at its labs in Adastral Park, Ipswich. That trial involved a 10km-long hollowcore fiber from Lumenisity.
Lumenisity was spun out of the Optoelectronics Research Centre at the University of Southampton in 2017, with an aim to commercialize the development of hollowcore fiber.
In 2020, the startup closed a £7.5 million ($9.77 million) funding round from a group of investors that included BGF and Parkwalk Advisors and existing industrial strategic investors. Lumenisity has raised £12.5 million (US$16.28 million), according to Crunchbase.
Some key application areas Lumenisity has identified for its technology include financial, data center connectivity and connectivity for the separation of remote radio units and baseband units in 5G networks.
About Comcast Corporation:
Comcast Corporation (Nasdaq: CMCSA) is a global media and technology company that connects people to moments that matter. We are principally focused on broadband, aggregation, and streaming with 57 million customer relationships across the United States and Europe. We deliver broadband, wireless, and video through our Xfinity, Comcast Business, and Sky brands; create, distribute, and stream leading entertainment, sports, and news through Universal Filmed Entertainment Group, Universal Studio Group, Sky Studios, the NBC and Telemundo broadcast networks, multiple cable networks, Peacock, NBCUniversal News Group, NBC Sports, Sky News, and Sky Sports; and provide memorable experiences at Universal Parks and Resorts in the United States and Asia. Visit www.comcastcorporation.com for more information.
David McGuire 215-422-2732
Lumenisity® Limited was formed in early 2017 as a spin-out from the world-renowned Optoelectronics Research Centre (ORC) at the University of Southampton (UK) to commercialize breakthroughs in the development of hollowcore optical fibre. We have built a team of industry leaders and experts to realise our goal to be the world’s premier high-performance Hollowcore fibre optic cable solutions provider, offering customers reliable, deployable, low latency and high bandwidth connections that unlock new capabilities in communication networks.
Lumenisity is well funded by a consortium of industrial and private investors. We recently relocated our headquarters to Romsey, UK after a substantial investment was made in developing a state of the art manufacturing and testing facility. Our vision is to be the world’s premier high-performance hollowcore fibre optic cable solutions provider offering our customers reliable, deployable, low latency and high bandwidth connections that unlock new capabilities in communication networks.
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2 thoughts on “Comcast Deploys Advanced Hollowcore Fiber With Faster Speed, Lower Latency”
Innovative UK fibre tech firm Lumenisity has landed a significant breakthrough deployment of its hollowcore fibre at major US cable broadband giant Comcast, which has about 30 million residential broadband customers. The revolutionary fibre, developed by the start-up that was spun out of Southampton University in 2017, delivers “significantly lower latency than traditional fibers and over time will provide critical performance attributes,” notes Comcast, which says the new tech will “support the delivery of multigigabit speeds through 10G.” Elad Nafshi, EVP & Chief Network Officer at Comcast Cable, noted: “Hollowcore fiber is a leap forward in how we deliver ultra-fast, ultra-low latency and ultra-reliable services to customers. 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.” This is an amazing breakthrough for Lumenisity, which has also been involved in multiple trials at BT’s Adastral Park research complex in East Anglia, UK, where a 10-kilometre-long hollow, air-filled fibre cable is being assessed for potential benefits that might accrue from its use in the front haul portions of 5G network architectures and ultra-secure communications such as Quantum Key Distribution.
Jeff Baumgartner of Light Reading:
Comcast is using a virtualized cable modem termination (vCMTS) and a distributed access architecture (DAA) to underpin a wave of multi-gigabit downstream speeds and enhanced upstream speeds in dozens of markets before the end of 2022. That work will serve as a springboard for the deployment of a more advanced DOCSIS 4.0 network that will start to deliver symmetrical multi-gigabit services in late 2023.
In concert with Wednesday’s launch of 2-Gig downstream speeds and faster upstream speeds in Denver, Comcast showed off some of its handiwork with city leaders and some media here at a headend that houses some of the new technologies that are making its new network go.
Currently based on DOCSIS 3.1, the access network that is delivering those new capabilities features a vCMTS paired with a distributed access architecture (DAA) powered by fiber nodes outfitted with remote PHY devices (RPDs). That will place PHY layer functions of traditional CMTS at the edge of the network and boost capacity by digitizing the HFC network all the way to the node.
Comcast is also boosting the DOCSIS upstream with a “mid-split” upgrade that expands the amount of spectrum dedicated to the upstream – from a legacy range of 5MHz-42MHz to a wider range of 5MHz-85MHz.
This week’s launch in Denver tied into Comcast’s plans to launch 2-Gig downstream speeds along with 5x to 10x faster upstream speeds (up to 200 Mbit/s) to 34 cities and towns before the end of the year. Similar upgrades are underway in markets such as Colorado Springs; Baltimore; Philadelphia; Hartford, Connecticut; Augusta, Georgia; Panama City Beach, Florida; Salt Lake City, Utah; and Washington, D.C.
“Our network upgrade is in full swing,” Elad Nafshi, Comcast’s EVP and chief network officer, said here during a briefing.
Comcast initially is limiting access to the new, faster upload speeds to customers who take xFi Complete, a package that sells for an additional $25 per month that includes Comcast’s gateway, its advanced cyber security product, Wi-Fi controls and unlimited data.
DOCSIS 4.0 update
Those 2022 market upgrades are setting the stage for a move to DOCSIS 4.0 and the introduction of symmetrical multi-gigabit speeds. Comcast plans to introduce that capability in select markets in the second half of 2023 and to bring them to more than 50 million homes and businesses before the end of 2025.
Comcast announced earlier this week that it had completed its first “live” DOCSIS 4.0 trial in the Philadelphia area. It marked the first time Comcast delivered a DOCSIS 4.0-based service to a subscriber location, Nafshi said.
The trial connection, which delivered symmetrical speeds of 4 Gbit/s, ran off of Comcast’s vCMTS outfitted with DOCSIS 4.0 code in tandem with DOCSIS 4.0-based remote PHY devices and modems, he said.
The Philadelphia trial used a “node+0” architecture, whereby fiber is pulled deep enough so there are no amplifiers required between the premises and the node. Comcast is also developing an FDX Amplifier that will enable the operator to deploy DOCSIS 4.0 to the vast majority of its HFC network, including portions of the plant that have multiple amplifiers (up to six, and potentially more) present between the home and the node.
Nafshi said the FDX Amplifier is still in development, but “there’s lots more to come on that in 2023.” CommScope, a key vendor partner on that project, showed a prototype FDX Amplifier in October at the SCTE Cable-Tec Expo in Philadelphia.
As Comcast looks ahead to D4.0/FDX deployments in 2023, Nafshi confirmed to Light Reading that the operator will base it on HFC networks built to 1GHz (the FDX specs support bandwidth up to 1.2GHz).
Nafshi said Comcast doesn’t feel the need to upgrade capacity to 1.2GHz at this point. “Everything can fit under the 1-Gig umbrella,” he said. However, he points out that taps being deployed today are capable of supporting 1.2GHz.
Comcast, he added, will be able to generate the speeds delivered at its D4.0 demo at CableLabs in April (8.5 Gbit/s downstream and 5 Gbit/s upstream) with the 1GHz configuration, and “roll this out broadly.”