Cox SVP: Multi-gig coming in late ’23, DOCSIS 4.0 in ‘25

Cox Communications is usually pretty private about its network plans, but SVP of Engineering Guy McCormick opened up in an exclusive interview with Fierce on Thursday. Among other notable reveals: the percentage of fiber in Cox’s network is “significant” and growing, and the operator expects to begin deploying extended spectrum DOCSIS 4.0 in 2025.

McCormick dished on a wide range of topics, including everything from the operator’s HFC upgrade progress and DOCSIS roadmap to its plans to increase speeds for consumers and trot out more greenfield fiber.

According to the SVP, Cox currently has DOCSIS 3.1 deployed across 100% of its footprint, allowing it to offer gigabit services to 99% of its customers. But it isn’t stopping there. Upgrades to a distributed access architecture (DAA) are well underway, with Remote PHY devices (RPDs) deployed across a little more than 50% of its network – a percentage McCormick said equates to “tens of thousands” of nodes.

A large portion of Cox’s RPDs are enabled with mid-splits. And they may remain that way for some time even as the operator begins to enable high splits later this year, he added.

The move to mid- and high-splits is an interim step on Cox’s road to extended spectrum DOCSIS 4.0 (ESD), which McCormick said will allow it to bring faster speeds to market. He noted it already has an asymmetrical 2-gig offering in trials and is “pretty confident” it can enable as much as half of its footprint with those speeds by the end of 2023.

From there, he said Cox could bump download speeds even higher – to 3 or even 4 gigs – by combining 1.2 GHz of spectrum with DOCSIS 4.0 CPE, though upstream speeds would top out at 1 gig. McCormick said there would be limitations on the degree of penetration it could achieve with such an offering due to node sizes, but the operator still thinks it’s a product that could come to market sometime in 2024.

DOCSIS, a story of and not or

As operators move to DOCSIS 4.0, there are two options to choose from: the aforementioned ESD technology, which Charter and others have chosen and a full duplex variant (FDX), which has notably been championed by Comcast. The latter involves the simultaneous transmission of data upstream and downstream using the same spectrum and requires new amplifiers, which include echo cancellation technology.

McCormick said Cox embraced ESD for a number of reasons. Investments in RF expansions are familiar to cable operators, he noted, something Cox already knows how to do well and a step that is consistent with its existing tooling, internal processes and technician training.

“When we evaluated FDX, we recognized we would be deploying some relatively complex technologies. Although there’s nothing new about echo cancellation as a technology, the application of that in an HFC network certainly introduces complexities we don’t deal with or operate today,” he explained. “So now you’re having to do a number of things from not only retooling but also skilling and uptraining technicians to work and operate in that environment…Then of course, there’s the sophistication and the complexity that comes into play with the amplifiers and then the situation where you have to create isolation groups in the DOCSIS domain.”

In May 2022, Cox executives said the operator was testing ESD technology in the lab. McCormick said lab tests are ongoing as are field tests as Cox explores RF characteristics like attenuation, powering and ingress and what impact those might have on the need for cable replacements.

McCormick said a joint development agreement Cox signed with Broadcom related to DOCSIS 4.0 silicon will be completed at the end of this year. The operator expects to have preproduction silicon in early 2024, begin field trials in the second half of next year and will likely start rolling out DOCSIS 4.0 commercially in early 2025. While others have more aggressive deployment timelines, McCormick said Cox’s goal is not to be at the bleeding edge but to wait until the technology is dependable.

He also stressed that although Cox is planning to lead with ESD for its DOCSIS 4.0 rollout, it sees the network of the future combining both ESD and FDX technologies. Rather positioning DOCSIS 4.0 as a story of FDX or ESD, McCormick said “it’s an and.”

“I really can see a convergence of ESD and FDX out in the future. That would be our [DOCSIS] 4.1 or 5.0 specification,” he said. “A 1.8 GHz network that has duplex capabilities inherently or built in, that’s a tremendous amount of capacity.”

Where fiber fits in

McCormick said fiber is another technological arrow it’s not afraid to pull. He noted Cox made the decision to use fiber for its greenfield builds about eight years ago using Remote OLT technology. Today, he said around 80% of its new builds are XGS-PON fiber and the “vast majority” of its grant projects will also use fiber. The latter is in part because in order to win support, Cox’s project bids have to use fiber, he added.

In terms of the scale of its fiber assets, McCormick said they’re now a "significant" percentage of its overall network. “It’s becoming meaningful,” he said. “We’re at a transition point where it’s become material enough where we’re starting to think different about how do we market those particular areas and leverage the message of fiber.”

Last year, Cox said it planned to reach more than 100,000 un- and under-served locations as part of a broader $400 million rural expansion project. Cox’s rural build includes more than 8,000 locations scattered across Arizona, Arkansas, California, Kansas, Louisiana, Nebraska, Nevada, Oklahoma and Virginia for which it won around $6.6 million in Rural Digital Opportunity Fund (RDOF) support in 2020.

In 2022 the operator added to that tally with state-level funding for projects in Arizona ($8.2 million), Oklahoma and Virginia. And thus far in 2023, the operator has won grants totaling $16.2 million in Florida to reach more than 6,800 locations, nearly $6.4 million in Kansas to cover 1,308 locations and just under $14.3 million in Arkansas. For its projects in Florida, the award release notes Cox is planning to deploy fiber to the home.

But McCormick said it’s also open to using fiber in brownfield territory, not only to better serve commercial areas, apartment complexes and high-usage neighborhoods, but also to fend off competition. In the latter case, that could mean overbuilding its HFC network with fiber to stay competitive.

“Where we face situations or environments where fiber overbuilds or fiber builds are the right long-term decision for this company, we will pull that lever,” he concluded.


This story has been updated to correct the percentage of fiber in Cox's network. A representative told Fierce after publication that McCormick's statement that the percentage of fiber in the network was "approaching double digits" was inaccurate.