Nearly three years after CableLabs first opened the door to its official DOCSIS 4.0 certification program, giving modem vendors and network gear providers a formalized environment to test and validate their next-generation technologies, the industry may finally be on the verge of welcoming its very first officially certified product.
Since launching the testing framework in 2023, the research and development consortium has conducted several interoperability tests and even awarded verifications proving that DOCSIS 4.0 modems can successfully operate on legacy DOCSIS 3.1 networks. Yet, despite steady progress across the supply chain, no hardware has yet crossed the finish line to receive the official DOCSIS 4.0 certification stamp.
That status quo could soon change, according to Mark Bridges, the chief technology officer and president of CableLabs, who is slated to succeed Phil McKinney as chief executive officer on January 1, 2027. Speaking in an interview ahead of the SCTE TechExpo in Atlanta, Bridges pointed to tangible improvements in the technological maturity of the broader ecosystem as a primary driver behind the imminent milestone.
"We’ve seen the maturity of the ecosystem really improve," Bridges said, citing the positive outcomes of recent DOCSIS 4.0 interoperability testing focused on advanced security protocols, alongside early performance indicators from initial commercial rollouts by cable operators deploying pre-certified equipment. "We’re very close on getting to our first certification."
For manufacturers and suppliers, navigating the certification journey carries distinct financial implications. Under CableLabs’ testing policies, suppliers that submit products for DOCSIS 4.0 certification remain in perpetual testing until they achieve success, sparing them from having to resubmit under rigid wave-by-wave testing schedules.
That continuous framework helps vendors manage escalating certification expenses. According to official CableLabs documentation, the initial submission fee for a DOCSIS 4.0 cable modem certification test runs $195,000 for devices utilizing either the Full Duplex (FDX) or Frequency Division Duplex (FDD) variants of the specifications. For combination devices incorporating both FDD and FDX technologies, the initial submission fee rises to $245,000. By comparison, initial certification testing for a legacy DOCSIS 3.1 modem, including DOCSIS 3.1+, sits at $145,000, with additional costs of $75,000 required for device updates or $70,000 for core phase updates.
DOCSIS Certification Still Critical
Even as the industry evolves and interoperability testing becomes more prominent, questions occasionally arise regarding whether full certification testing remains strictly necessary. Collaborative interoperability events help ensure that customer premises equipment from disparate suppliers, alongside network hardware and software, function harmoniously together. Furthermore, the retail market for DOCSIS cable modems—which legally require certification prior to commercial sale—remains relatively small. Jeff Heynen, vice president of broadband access and home networking at Dell’Oro Group, estimates that retail channels account for less than 20% of total DOCSIS customer premises equipment shipments.
Despite these dynamics, Bridges emphasized that comprehensive DOCSIS certification, including the upcoming milestone for version 4.0, remains an indispensable pillar of the cable industry.
The rigorous certification process ensures that the entire DOCSIS ecosystem adheres to uniform standards of excellence. Moreover, it delivers a vital, security-focused public key infrastructure certificate that serves as a dependable mark of quality and operational assurance for both network operators and hardware vendors.
"With DOCSIS, security is built into the protocols. It is not intended to be an optional element," Bridges said. "We manage the certificate authority for those certificates that handle secure communications. That is still a major part of our operations."
Heynen concurred that certification continues to hold significant value, particularly for regional and independent operators that do not maintain their own independent testing laboratories, unlike industry giants such as Comcast and Charter Communications, which operate internal qualification programs. However, Heynen noted that verified for interoperability testing—which covers DOCSIS 4.0 modems operating over existing DOCSIS 3.1 plant infrastructure—may prove entirely sufficient for operators that have no immediate plans to upgrade their physical networks to full DOCSIS 4.0 architectures.
Thus far, the absence of an officially certified DOCSIS 4.0 device has not hindered broader commercial deployments or suppressed equipment sales. According to one supplier executive, the lack of a formal stamp has created minimal friction in the market, describing the certification as "a box they want eventually" rather than an immediate roadblock to business.
Pushing Boundaries: 25-Gig and Beyond on HFC
Even as the first wave of certifications looms, Bridges and his engineering teams at CableLabs are already laying the groundwork for the next evolutionary chapter of hybrid fiber-coaxial networks. The organization recently introduced an optional annex to the DOCSIS 4.0 specifications focused on expanding usable spectrum up to 3GHz—a significant leap from today’s state-of-the-art 1.8GHz deployments—with the ultimate goal of enabling downstream speeds of 25 Gbps and potentially higher.
Alongside these newly released specifications, CableLabs is actively conducting advanced modeling to explore the physical behavior of coaxial networks at 6GHz. Successfully harnessing this ultra-high frequency range could eventually push downstream speeds past 50 Gbps on legacy hybrid fiber-coaxial infrastructure.
Much of the investigative work surrounding 6GHz remains in the early research phase. Engineers are confronting the complex task of designing new amplifiers capable of handling these extreme frequencies while managing increased power consumption demands. Among the various components required for such an upgrade, development work on 6GHz-capable taps has progressed the furthest, according to Bridges.
DOCSIS Reliability a ‘Top Focus’
Looking ahead to his upcoming tenure as chief executive officer, Bridges stressed that CableLabs and its member organizations are placing an intense, renewed emphasis on the fundamental reliability of DOCSIS networks.
"That’s a top focus for us right now," Bridges said, pointing out that the deployment of DOCSIS 4.0 technology alongside ongoing distributed access architecture upgrades are explicitly engineered to deliver generational leaps in reliability as optical fiber is pushed deeper into neighborhood architectures.
This dedication to operational stability may prompt further addendums and refinements to existing DOCSIS specifications. "It’s really about looking to make sure we haven’t left anything on the table in terms of pushing the absolute limits of reliability," Bridges noted.
This strategic focus will also encompass the broader domain of network convergence, which traditionally refers to bundled service packages combining home broadband and mobile connectivity. Bridges indicated that significant engineering work remains ahead to develop sophisticated technologies and software systems that support true convergence. This includes advanced tracking, management of connectivity parameters, and seamless subscriber policy enforcement as devices transition fluidly between Wi-Fi hotspots and terrestrial cellular networks. CableLabs is continuing its multi-faceted efforts to make these handoffs increasingly transparent and frictionless for end users.
In parallel, CableLabs is expanding its footprint in artificial intelligence, a tool that network operators are already leveraging to optimize back-office operations and elevate customer service standards. Upcoming initiatives will involve collaborating on established best practices and system architectures for artificial intelligence agents, building directly upon CableLabs’ existing AI for operations framework.
‘Cable’ and ‘Labs’: The Enduring Couple
As the telecommunications landscape shifts toward technology-agnostic service delivery, several prominent industry organizations have opted to drop the word "cable" from their titles or event designations as operators increasingly deploy fiber-to-the-premises and wireless mobile infrastructure. Even the recently rebranded SCTE TechExpo, which now incorporates "convergence" and "experience" into its official subtitle, was widely known as the Cable-Tec Expo prior to 2024.
Given that CableLabs itself is dedicating substantial resources to passive optical networking technologies like XGS-PON and various wireless paradigms, questions occasionally arise regarding whether the organization might eventually drop "cable" from its corporate moniker.
"It comes up a lot," Bridges acknowledged. "Right now, there are no plans to make changes to the branding."
