The latest DOCSIS® 4.0 interop event wasn’t just another gathering of broadband innovators — it was another significant step forward for the industry.

With more than 50 attendees from around the globe, the energy in the room was palpable. This event wasn’t just about checking boxes for protocol compliance; it was about pushing the limits of broadband technology and seeing what happens when the brightest minds and the fastest modems in the business are brought together at CableLabs.

The Interop·Labs event, held Aug. 11–14 at CableLabs headquarters, gave suppliers an opportunity to verify interoperability between equipment designed to comply with DOCSIS 4.0 specifications. It focused on three key areas: speed, stability and a diverse ecosystem. Each of these components directly impacts the quality and reliability of broadband service.

Ten Modem Suppliers, One Goal

One of the standout aspects of this interop was the 10 participating modem suppliers. Each supplier brought their own unique hardware and firmware optimizations to the table, creating an environment where innovation could thrive.

Once again, attendance at the event was the highest yet and included three operators on hand to observe demos and share their DOCSIS 4.0 network progress.

Three suppliers — CommScope, Harmonic and Vecima — brought DOCSIS 4.0 cores to the event. Again, we saw five Remote PHY Device (RPD) platforms from Calian, CommScope, Harmonic, Teleste and Vecima. And, of course, the icing on the cake was the number of DOCSIS 4.0 modem suppliers in attendance — Arcadyan, Askey, Compal, Gemtek, Hitron, Sagemcom, Sercomm, Ubee, Vantiva and WNC — who brought multiple modem models.

Chipmakers Broadcom and MaxLinear brought local engineering support for their cable modem partners, and Calian participated with its test solutions.

Every supplier was aligned on one common goal: proving that DOCSIS 4.0 technology is not simply a theoretical leap forward but that it is a commercially viable technology ready for wide-scale rollout. The interoperability tests weren’t simply about passing; they were about performance headroom, feature robustness and forward-compatibility.

And the results? Let’s just say fast doesn’t even begin to describe it.

The Showstopper: 16 Gbps Downstream

If there was a single number everyone walked away talking about, it was 16 Gbps downstream. Achieving this kind of throughput in a lab environment is one thing; demonstrating it live in a collaborative interop environment — across multiple suppliers — is something else entirely.

This wasn’t an isolated “best case” setup either. Several configurations reached double-digit gigabit speeds, showing that DOCSIS 4.0 technology isn’t just an incremental step — it’s a foundation for multigigabit service tiers that can compete head-to-head with fiber.

Collaboration Is the New Competition

Perhaps the most inspiring part of the event wasn’t the hardware or the speed tests — it was the culture of collaboration. Ten different modem suppliers, each with their own market goals, came together to ensure that when DOCSIS 4.0 technology hits the field, it will work seamlessly across the ecosystem. The modems spent most of the interop working on the three cores, driving interoperability across the wider ecosystem with the RPD suppliers.

This spirit of cooperation ensures that innovation isn’t locked in silos. When suppliers solve interoperability challenges together, operators and consumers benefit from a smoother, faster rollout of next-gen services.

Additional Cable Modem PNM Operations

With a record number of modems in attendance, we rolled out the proactive network maintenance (PNM) tests for the modems. More and more, the signals on the plant are orthogonal frequency division multiplexing (OFDM) and orthogonal frequency division multiple access (OFDMA), which provide higher speeds and capacities than traditional quadrature amplitude modulation (QAM) signals.

At this interop, we ran five PNM tests on the modems, specifically getting data from DOCSIS 4.0 modems and verifying interoperability with the application programming interfaces (APIs) and with the data generated by the modems. This PNM data will enable the most efficient operation of the coaxial cable network, keeping the data levels at their peak by using the more efficient OFDM and OFDMA signals.

DOCSIS 3.1 Plus: Beyond the Buzzword

DOCSIS 3.1 Plus (DOCSIS 3.1+) was also prominent at the interop with several modems in attendance. The leap from DOCSIS 3.1 to DOCSIS 3.1+ is about raw speed. The “Plus” brings expanded support for more OFDM channels, which means more downstream speed. More than slides in a presentation, these advancements were tested, measured and verified in real time.

Operators are already discussing how these capabilities could fit into their network evolution plans. With the cost efficiency of leveraging existing HFC plant and the performance benefits on display, DOCSIS 3.1+ has emerged as a compelling strategy for rapid, wide-scale multigigabit deployment.

What’s Next

With the success of this record-breaking interop, the stage is set for even more ambitious goals. The industry now has proof that multi-vendor DOCSIS 4.0 systems can deliver and play nicely together. The next steps will likely include refining firmware for even better efficiency and starting the migration path toward DOCSIS 4.0 technology.

There are lots of moving parts in these interops, but one thing is certain: the 16 Gbps milestone will be remembered not just for the number but for what it represents — the moment when the industry saw the future of HFC networks and realized it was already within reach.

This interop wasn’t just an event — it was a benchmark for the broadband industry’s future. With record attendance, diverse vendor participation and real-world proof of DOCSIS 4.0 capabilities, the path to multigigabit broadband has never been clearer.

Another DOCSIS 4.0 interop is planned for the week of Oct. 20 at CableLabs. Consider joining us to see the speed and service possibilities firsthand!

Learn More at SCTE TechExpo

There’s still time to join us at SCTE TechExpo25, Sept. 29–Oct. 1, 2025, in Washington, D.C. Employees of CableLabs member companies are eligible to receive a complimentary full-access pass. Register today if you haven’t yet!

If you’re attending, plan to attend “Self-Healing Networks: The New Frontier of DOCSIS Operations” on Monday, Sept. 29. In this session, my CableLabs colleagues will join a conversation on how PNM and Profile Management Application (PMA) technologies can create intelligent, self-optimizing networks that proactively detect issues, adapt performance in real-time and shift operations from reactive troubleshooting to automated network resilience.