CableLabs has published the anticipated specifications for DOCSIS 4.0, the next technology standard for moving data across the cable industry’s hybrid fiber/coaxial (HFC) networks. 

The new specification, which is an upgrade over the cable industry’s current DOCSIS 3.1 standard, will enable operators to deliver download speeds of up to 10 gigabits per second. Upstream speeds can approach speeds of 6 Gbps. 

Importantly, DOCSIS 4.0 provides a unification of two competing technologies for moving HFC networks to 10-gig speeds. Explained here in detail in a 2017 CableLabs blog post, Full Duplex DOCSIS would combine downstream and upstream signals on a single frequency, delivering symmetrical speeds up to 10 Gbps. Full Duplex is favored by the leading U.S. cable operator, Comcast, but its stringent network technology requirements made it economically infeasible for many operators.

Extended Spectrum DOCSIS (blogged about by CableLabs in September here) keeps upstream and downstream traffic separate. But it would increase the spectrum of HFC networks to 1.8Ghz from a current level of 1.2Ghz found on the fastest networks. 

CableLabs is the technology consortium for the major U.S. cable companies. And it’s serving a broader cable industry initiative called “10G,” an effort to migrate cable networks to a future in which 10 Gbps speeds power increased cloud applications, video conferencing, smart homes and distance learning—a future that is, well, here to today for many of us. 

But don’t look for commercial deployments of DOCSIS 4.0 networks by operators in the months to come. Cable operators still have a glut of network capacity from huge investments made over the last five years in DOCSIS 3.1 infrastructure. These buildups enabled them to offer customers the 1 Gbps speeds, the ceiling for which consumers are no where near bumping into just yet. 

But DOCSIS 4.0 does give cable industry engineers in purchasing roles clarity on how to move forward in a network technology realm being disrupted by virtualization and Distributed Access Architecture (DAA). 

“With the DOCSIS 4.0 specification establishing a clear path forward, giving cable operators the flexibility to pursue either Extended Spectrum DOCSIS (ESD) or Full Duplex DOCSIS (FDX), operators can move ahead with their remote PHY and remote MACPHY deployments to solve immediate head-end and power consumption issues,” wrote Dell’Oro Group analyst Jeff Heynen, in a blog post published two weeks ago. 

Making its first appearance at Cable-Tec Expo Show following its purchase of Arris earlier this year CommScope will present three technologies it believes will provide clarity for cable engineers to finally make some forward-looking decisions about their networks ... and start rendering some product orders.

Extended Soft Frequency Division Duplex (FDD) blends elements of Full Duplex DOCSIS and Extended Spectrum DOCSIS, two technologies cooked up by CableLabs to extend the life of hybrid fiber coaxial networks into the next two decades. 

In fact, Chris Busch, CommScope engineering fellow in the office of the CTO, calls Extended Soft FDD “the union of the two technologies,” allowing operators to adjust allocation of bandwidth across the upstream and downstream channels.

Full Duplex DOCSIS has the capability of delivering symmetrical 10 Gbps speeds. But its uptake has been limited by what are perceived to be some inflexible factors.

“If we’re going to make Full Duplex work for us as industry, we need to have ability to use spectrum in many different use cases,” Busch said.

He added that unlike FDX, CommScope’s trials of Extended Soft FDD have revealed no rigid need for a node plus zero network configuration.

“A lot of Extended Soft FDD is amplifier friendly,” Busch said. “It’s a boon to the operator.”

CommScope will make its pitch next week amid a slow sales year for cable access technology vendors in general.

Also speaking to MCN Monday, Todd Kessler, senior VP of product management for CommScope, noted that the shift from centralized integrated CCAP architecture to Distributed Access Architecture (DAA) is one of the biggest technological changes the cable industry has ever made. He believes CTOs will continue to mull these decisions through the calendar year.

To hopefully move the market along, CommScope will also present what it calls DAA Aggregator, a product that lets operators connect up to eight HFC nodes to one Remote PHY device. This significantly increases the number of homes passed per RPD serving group—from 20 to 40 to between 150 to 300—enabling deeper reach into neighborhoods and a simplified path to network upgrades.

Also being demonstrated: DOCSIS Timing Protocol uses precise timing distribution over the DOCSIS networks for time-critical processing and applications, where a fraction of a second means the difference between success and failure. Current and future applications include mobile backhaul, virtual reality, and autonomous vehicle control.

“This is all built around driving the cable operators to better utilize their HFC plant, and breath new life into HFC architecture, taking fiber deeper, and adding to the technology,” Kessler said.