The next standard for cable broadband is due around 2025.

Just as the cable industry is widely introducing gigabit download speed supported by DOCSIS 3.1 technology, cable engineers are working on a way to boost upload and download speeds to as high as 60 Gbps (60,000 Mbps) starting as soon as 2025.

According to a new article in Light Reading, DOCSIS 4.0 (or DOCSIS.Next) represents a transformational leap of cable broadband technology. Jeff Finklestein, Cox Communications’ executive director of advanced technology, claims the next major broadband update will be able to use at least 3 GHz of RF spectrum available on existing coaxial cable for high-speed internet. That is more than twice the 1.2 GHz that being used by some cable systems for today’s DOCSIS 3.1 (and the 1.8 GHz that will be needed to support DOCSIS 3.1 FD, which will allow operators to dramatically boost upload speeds by 2020.)

Designed for the next decade, DOCSIS 4.0 will support 30/30 Gbps speed (or 60/60 Gbps if an operator is willing to dedicate up to 6 GHz for broadband). Today’s coaxial cable networks can use up to 10 GHz of RF spectrum in all, with some compromises and allowances to deal with possible signal ingress and other types of interference.

By the time DOCSIS 4.0 arrives, many cable operators will not mind delivering the majority of their available spectrum to broadband, because most are expected to eventually deliver a single broadband stream that collectively supports IPTV, digital phone, and broadband service.

Finklestein

To make the next generation of cable broadband possible, cable systems will likely need to reduce the amount of copper coaxial cable in their networks and push fiber optics deeper into neighborhoods. The more optical fiber the better — the technology is not hampered by coaxial cable’s limitations and degradation.

Engineers are also likely to shift away from DOCSIS 3.1’s orthogonal frequency division multiplexing (OFDM) modulation and use advanced wave form technology instead.

While engineers are excited about the project, some suspect DOCSIS 4.0 may be a tougher sell for cable industry executives, asked to invest in another transformational broadband upgrade less than ten years after DOCSIS 3.1 was introduced. Many cable operators using older cable network plants will have to spend millions on overhauls and upgrades, and there is some question about whether that kind of additional investment in a Hybrid Fiber Coax (HFC) network platform makes sense. Altice certainly does not believe so, and in 2016 elected to scrap Cablevision/Optimum’s HFC network and replace it with fiber to the home service.

As cable companies push fiber deeper into their networks, the cost of taking fiber the rest of the way to customer homes and businesses is coming down as well.

The cable industry has generally dismissed fiber to the home service as an extravagant and expensive technology to deploy, arguing cable’s HFC networks can deliver the broadband speeds that are commercially in demand today, while working on upgrades like DOCSIS 4.0 to meet consumer and business demands tomorrow, without the cost of tearing up streets to lay optical fiber.