Prepare for DOCSIS 4.0: Don’t Let Hidden Signal Loss Undermine Performance

The world is hungry for ever more data. It’s a never-ending cycle that poses ongoing challenges for today’s cable multiple system operators (MSOs) and the hybrid fiber-coaxial (HFC) networks they operate. From 4K/8K streaming video to remote work, smart home and IoT expansion, the constant end-user demand for more data is pushing MSOs to stay ahead by enabling their existing networks to handle ever-increasing speeds and capacities.

At the forefront of this perennial challenge is DOCSIS 4.0, the industry’s next-generation cable broadband standard featuring multi-gigabit symmetrical speeds, lower latency, and greater network efficiency. For HFC operators, DOCSIS innovations are a critical tool in the push to stay competitive with pure fiber-to-the-home (FTTH) networks. Asa result, a number of MSOs are focusing on DOCSIS 4.0 rollouts as a long-term growth strategy, expanding usable spectrum and enabling speeds of up to 10Gbps to the home.

Yet, we see a challenge. With all the excitement around the leap from DOCSIS 3.1 to DOCSIS 4.0, much of the conversation currently centers on the DOCSIS technology itself – the traffic that flows through the network. What’s currently at risk of being overlooked is the underlying physical infrastructure that enables and supports DOCSIS 4.0 services – the highway on which the traffic travels.

This is where Belden’s broadband brands come in. In this blog, we’ll explore how minimizing signal loss in physical network components is critical in enabling today’s HFC networks to handle the rigorous demands of DOCSIS 4.0 and beyond.

DOCSIS4.0: How Does it Expand the Digital Highway?

In simple terms, DOCSIS is a standard that lets network operators send IP traffic (Internet, VoIP, streaming, etc.) over a radio frequency (RF) network using coaxial and HFC infrastructure. With each evolution, CableLabs has focused on increasing data capacity and efficiency. Here’s a brief look at the history of DOCSIS.

Earlier versions of DOCSIS, like 3.0, used dedicated, fixed RF channels to deliver data downstream and upstream. While multiple, narrow channels (typically 6 or 8 MHz wide) could be combined to boost capacity (a technique known as channel bonding), they were still separate, dedicated lanes. Think about it like this; Each downstream and upstream channel is like a separate, one-way road of fixed width. While multiple roads could be gathered to make a bigger route, each car needed to stay in its fixed lane – no changing allowed even if one road was blocked or noisy.

DOCSIS 3.1 and 4.0 are much different – a complete paradigm shift. Instead of using fixed single-carrier QAM channels like previous iterations of DOCSIS, these modern standards leverage a technique called Orthogonal Frequency-Division Multiplexing (OFDM). OFDM uses a much wider block of spectrum that gets subdivided into hundreds or thousands of narrow subcarriers that can be dynamically allocated, modulated or otherwise adjusted based on capacity needs, noise or interference. Returning to our roadway metaphor, OFDM turns those narrow one-way roads into a big, multi-lane highway that allows traffic (the data packets) to flow in an optimal way for speed, reliability and efficiency.

As a result of restructured channel specifications, DOCSIS 3.1 and DOCSIS 4.0 offer significant performance upgrades relative to older standards. Consider the following table to understand the evolution of DOCSIS from 3.0 to 3.1 and now 4.0.

With increased downstream data rates and significantly augmented upstream capacity, DOCSIS 4.0 sets cable operators up to deliver the services their customers want, for years to come. As a result, MSOs are beginning to look at moving from DOCSIS 3.1’s 1.2 GHz systems to DOCSIS 4.0’s 1.8 GHz architecture as they seek to meet growing end-user demands for higher bandwidth and lower latency applications.

Avoid the Cost of Signal Loss Within the Physical Layer

While the specifications of DOCSIS 4.0 are impressive, they push MSOs and other HFC network operators to pay increased attention to signal loss within the physical layer of their networks. Here’s why.

As network operators push signals to higher frequencies, they naturally end up with more signal loss over the same length of cable. For example, a 100-foot coax cable that loses about 10 decibels at 1GHz could lose nearly twice that at 3 GHz. The natural inclination is to solve this by relying on signal amplification. Obviously, more loss requires stronger amplifiers. However, those relying on this strategy will run into issues quickly.

As operators upgrade their networks to handle higher speeds, the usual approach is simply to swap out old amplifier modules with new ones that can handle higher frequencies. It’s often viewed as simpler and more cost effective than re-splicing cables or digging up streets to lay new ones. From a plug-and-play perspective, the drop-in approach appears quite attractive. That said, every amplifier is designed to handle a certain maximum amount of signal loss, and manufacturers do not always have a version that can cover a bigger gap.

This boxes network operators into a difficult situation. They might try to add another amplifier elsewhere in the middle of the line, but that means a need for more equipment, more power, more maintenance and possibly new housing or cabinets. They might also try to shorten the distance between amplifiers, but this means more nodes, costly redesigns, and time needed in the field. The financial costs associated with signal loss at higher frequencies can be significant.

It’s also important to remember that signal loss happens not just in the cables, but in every connector and component along the way. Even half a decibel of loss per connector can add up fast for cable operators that have many of them in line. That total loss can make the signal path weak and inefficient, which could cancel out some of the expected gains from upgrading to a new DOCSIS version.

How Does Belden Pave the Way for High-Frequency DOCSIS?

At Belden’s broadband brand, PPC, we help MSOs and other HFC network operators build the robust, resilient data transport highways they need for advanced DOCSIS by producing components that ensure minimal signal loss across the expanded spectrum. Our commitment to minimizing loss has a direct and significant impact on network performance and, crucially, on cost efficiency.

Our NexBand™ Hardline Connectors, engineered for DOCSIS 4.0 and beyond, are rated for high performance up to 3 GHz, and fully optimized for 1.2 GHz and 1.8 GHz frequencies. Offering a tech-friendly design, including marked trim lengths, positive stop and active O-ring, they can be reused in the field without damage. The forward-thinking design of the NexBand™ Hardline Connectors ensures that PPC products are ready even before real-world MSO upgrades catch up with industry innovations such as 3 GHz Extended Spectrum DOCSIS (ESD).

By minimizing loss in these critical connectors, we’re helping network operators in an era of tight budgets and high expectations. Less signal loss means less need for expensive amplifiers and other significant, physical changes. By providing connectors that inherently minimize signal loss, existing amplifiers can operate more efficiently and without having to compensate for unexpected, component-related performance degradation. Beyond the NexBand™ family of connectors and adapters, we also offer SignalTight® EX6XLPLUS connectors, which are also adjusted to have minimal loss out to 3 GHz. With products like these, we’re helping MSOs ensure the integrity of the highway that DOCSIS 4.0 will rely on now and into the future.

Importance of Future-Proofing DOCSIS 4.0 Networks Intelligently

As network operators continue to cautiously test and roll out DOCSIS 4.0 capabilities, strengthening the physical layer of their networks is a critical strategy for long-term success. Central to this is solving the issue of signal loss at higher frequencies over the same link distances. Accomplishing this successfully requires a holistic evaluation of each component, especially connectors. As some of the biggest MSOs today begin the process of making the leap from DOCSIS 3.1 systems deployed at up to 1.2 GHz to 1.8 GHz DOCSIS 4.0 (while eyeing a potential move to 3 GHz down the line),employing future-ready connectors now will deliver significant dividends in the future. And that’s how DOCSIS solutions specialists, like us, can help – by providing the low-loss components to operators tackling this hurdle and readying their networks for future DOCSIS demands.