DOCSIS 4.0 certification is weeks or months away, according to Mark Bridges, the CTO and president of CableLabs who takes over as CEO on January 1, 2027.

"We're very close on getting to our first certification," Bridges said in an interview ahead of the SCTE TechExpo in Atlanta, citing improved ecosystem maturity and recent interoperability test results in security.

CableLabs opened the door to DOCSIS 4.0 certification testing in 2023. Since then, the group has run several D4.0 interoperability tests and issued verifications confirming that D4.0 modems can run on D3.1 networks. No product has yet carried the official D4.0 stamp.

What does certification cost suppliers?

A first-time submission for a DOCSIS 4.0 cable modem using the Full Duplex (FDX) or Frequency Division Duplex (FDD) flavor of the spec costs $195,000, according to CableLabs' certification fee schedule. A combination FDD/FDX device runs $245,000. A D3.1 modem submission, by comparison, costs $145,000.

Suppliers that enter the D4.0 queue stay in perpetual testing until they pass, rather than resubmitting on a fixed wave schedule. That structure limits repeat fees while products mature.

Why does certification still matter?

Some operators and vendors argue that interoperability testing alone is sufficient, since retail accounts for less than 20% of total DOCSIS CPE shipments, according to Jeff Heynen, vice president of broadband access and home networking at Dell'Oro Group.

Bridges pushes back. "With DOCSIS, security is built into the protocols. It is not intended to be an optional element," he said. CableLabs manages the certificate authority behind the public key infrastructure (PKI) that underwrites secure communications, a function he calls "a major part of our operations."

Heynen agreed certification carries weight for operators beyond Comcast and Spectrum, which run their own programs. For operators not upgrading to D4.0 soon, the verified-for-interoperability (VFI) path — covering D4.0 modems on D3.1 plant — should be enough.

What comes after DOCSIS 4.0?

CableLabs released specifications for an optional DOCSIS 4.0 annex that pushes usable spectrum to 3 GHz, from the current 1.8 GHz state of the art, and targets downstream speeds of 25 Gbit/s.

Bridges said modeling is also underway for behavior at 6 GHz, which could push hybrid fiber/coax (HFC) downstream past 50 Gbit/s. Work on 6 GHz-capable taps is the furthest along; new amplifiers must be designed to handle higher frequencies and power draws.

Where is CableLabs heading under new leadership?

Reliability tops Bridges' agenda when he assumes the CEO role. "That's a top focus for us right now," he said, pointing to D4.0 and distributed access architecture (DAA) upgrades aimed at improving uptime as fiber is pushed deeper.

Convergence — discounted bundles of home broadband and mobile — forms the second pillar. CableLabs is working on policy and connectivity management for subscribers and devices moving between Wi-Fi and cellular networks, with a goal of seamless handoffs.

AI work continues through the organization's AI for operations initiative, with new focus on best practices and architectures for AI agents.

Will CableLabs drop "cable" from its name?

The question surfaces regularly, Bridges acknowledged. "Right now, there are no plans to make changes to the branding," he said, even as the group expands work on PON and wireless. SCTE itself rebranded Cable-Tec Expo as SCTE TechExpo before 2024, adding "convergence" and "experience" to the tagline.

With the first D4.0 certification now in sight and a successor CEO named more than a year in advance, CableLabs is signalling a deliberate handover: locking down reliability on the HFC plant, opening the door to multi-gig PON and wireless research, and keeping the cable banner intact while the technology underneath it evolves.