Comcast, Charter and Broadcom take aim at 25-Gig on HFC

In a project that might turn into DOCSIS 5.0, Comcast, Charter and Broadcom are collaborating on a plan to use 'unified' DOCSIS silicon to deliver downstream speeds of 25 Gbit/s on the cable network by extending spectrum to 3GHz.

Jeff Baumgartner, Senior Editor

September 25, 2024

5 Min Read
Conceptual art of ones and zeroes flowing down a data stream or pipe
(Source: Science Photo Library/Alamy Stock Photo)

Comcast, Charter Communications and Broadcom appear to be on a collision course with what might someday become DOCSIS 5.0.

Comcast, Charter Communications and Broadcom said they are collaborating on a way to deliver downstream speeds of 25 Gbit/s on the hybrid fiber/coax (HFC) plant by extending spectrum to the lofty levels of 3GHz.

Update: Speaking Tuesday in Atlanta at the SCTE TechExpo show, execs at Comcast, Charter Communications and Broadcom confirmed that they indeed plan to help spearhead a plan to develop DOCSIS 5.0 specs.

Execs from Broadcom, Charter and Comcast discuss plans for DOCSIS 5.0 at TechExpo 2025 in Atlanta. SIS 5.0 at SCTE TechExpo 2024 in Atlanta. From left: Rich DiGeronimo, Charter;  Charlie Herrin, Comcast; and Charlie Kawwas, Broadcom,

That approach, which would nearly double the amount of bandwidth allocated for today's state-of-the-art 1.8GHz technologies, would also take advantage of new "unified" silicon from Broadcom that supports both Extended Spectrum DOCSIS and Full Duplex (FDX) – the two flavors of today's DOCSIS 4.0 specifications. In the ESD approach, upstream and downstream spectrum operates in separately dedicated spectrum, and FDX employs the use of a specialized band that's capable of running upstream and downstream traffic to run in the same block of spectrum.

The companies stressed that the advanced design under development would comply with current DOCSIS 4.0 specs and create a "foundation" for next-generation technologies that aim to deliver economies of scale, enable a "robust vendor ecosystem" and establish a streamlined approach to CableLabs certification and operator qualification.

Related:Cable's secretive 'NRoC' project explores way to run 5G on HFC

Embedded AI and ML

Aiming to further cable's current "10G" initiative, these advanced 3GHz, unified DOCSIS chips from Broadcom will be made to fit inside amplifiers, nodes and customer premises equipment (CPE).

Like Broadcom's current line of unified D4.0 chips, the 3GHz versions would also be equipped with artificial intelligence (AI) and machine learning (ML) engines that can pinpoint and, in some cases, auto-repair plant impairments and generally boost the reliability and performance of the HFC network. The chip will also embed cybersecurity measures to ward off attacks.

This new angle is also to allow operators to easily program how they are splitting upstream and downstream bandwidth based on the current day's data demands.

'Early planning stages'

The approach being explored is not yet symmetrical. Sources familiar with the plan say the initial focus is to pair a 25Gbit/s-capable downstream with an upstream that could deliver at least 5 Gbit/s upstream, with the potential to push that further as the technology is optimized.

The companies said the initiative is in the "early planning stages" and did not offer a specified timeframe for trials and commercial deployments. But people familiar with the idea tell Light Reading that it could take three years or more to reach fruition.

Related:Cable operators see surge in network upgrade options

Update: But Broadcom believes that it is much closer than that. "We absolutely intend to take this to production next year," Charlie Kawwas, president of Broadcom's semiconductor solutions group, said today at the show. "It's not slideware. This chip exists and it's on the floor."

Comcast is showing early versions of the technology at this week's SCTE TechExpo in Atlanta. CommScope was among the vendors showing off the idea at the show.

(Source: Jeff Baumgartner/Light Reading) CommScope 3GHz DOCSIS demo at TechExpo 2024 in Atlanta

The idea will face some special challenges in running broadband up to 3GHz, including increased power requirements and the likely need for pristine coax.

The exploration of 3GHz technology emerges as cable operators continue to face the threat of speedy fiber competition while exploring ways to extend the life and capabilities of their widely deployed HFC networks economically.

Word of the new project enters the fray as the cable industry is just now starting to ramp up deployments of DOCSIS 4.0. Comcast, which is first out of the chute with the FDX version of the specs, has deployed D4.0 to ten markets and about 1 million homes passed and plans to ramp up the deployment pace as it gains access to a commercially ready version of an FDX amplifier.

Related:Comcast, Broadcom chip in to unify DOCSIS 4.0

Fresh spin on an old idea

The 3GHz effort marks a fresh look at an idea that's been bouncing around the industry for some time. Light Reading reported in July that Broadcom was taking a closer look at the viability of delivering DOCSIS traffic on spectrum up to 3GHz. SCTE, the industry's standards-setting organization, formed a task force to explore 3GHz tech years ago.

The companies did not say if these new chips will require joint development agreements (JDAs) to gain access to the 3GHz technology, at least in the early going. Broadcom currently has JDAs in place for its current-gen unified D4.0 chipsets with a group of Tier-1 operators, including Comcast, Charter, Cox Communications, Liberty Global and Rogers Communications.

However, the plan appears to ensure that this new technology will eventually become available to other operators and their tech partners.

"Supporting a single technology that can be used by all operators efficiently, over their existing networks, allows the industry to leverage its collective investment, and to increase the benefits of AI at the edge," Charlie Herrin, president of technology, product and experience at Comcast, said in a statement.

About the Author

Jeff Baumgartner

Senior Editor, Light Reading

Jeff Baumgartner is a Senior Editor for Light Reading and is responsible for the day-to-day news coverage and analysis of the cable and video sectors. Follow him on X and LinkedIn.

Baumgartner also served as Site Editor for Light Reading Cable from 2007-2013. In between his two stints at Light Reading, he led tech coverage for Multichannel News and was a regular contributor to Broadcasting + Cable. Baumgartner was named to the 2018 class of the Cable TV Pioneers.

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