Broadband access networks on path to 1-terabit speeds by 2040 – Chapman

DENVER – CABLE NEXT-GEN – If past trends hold up, the broadband access network is poised to deliver speeds of 1 Tbit/s by 2040, DOCSIS pioneer and long-time Cisco Systems exec John Chapman predicted here during a keynote focused on "The Future of Broadband."

That forecast takes its cue in part from the evolution of Moore's Law, which sees chip density increase by two every two years; the rate of performance for technologies such as Ethernet and DOCSIS, which have been rising up by a factor of ten about every seven years; and the pace of optics advancements.

And that prediction also ties into what Chapman calls his "Three Laws of Broadband," which was presented here for the first time:

Chapman said these observations are backed by studying ten different business and technology trends: investment based on a sustainable market; the density and costs of ASICs; and SerDes (serializer/deserializer); optics; advanced modulation and digital signal processing techniques; the advancement of RF technology; the evolution and availability of fiber; and the emergence of a common IP and segment routing infrastructure.

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In today's 20-year cycle, he explained, broadband technology is currently in a seven-year 1 Gbit/s to 10 Gbit/s window – meaning an operator must offer speeds of 1 Gig to be considered a serious broadband provider, but doesn't yet have to make the leap to 10-Gig speeds. That speed window will be followed by another seven-year window in the range of 10 Gbit/s to 100 Gbit/s. That will then be followed by a speed window in the range of 100 Gbit/s to 1 Tbit/s.

(Source: 'The Future of Broadband', John Chapman, March 2024)

By way of example, Chapman, who is about to leave Cisco after a 34-year career there, noted that 1200-baud dial-up modems were in use back in 1980, 1 Mbit/s services emerged around 2000, and 1-Gig speeds showed up in force by about 2020.

"It fit," he said of his 20-year calculations. "If you agree with those observations, if that's really what's happening and how technology is driving things ... if we're at a gigabit in 2020, that suggests we'll be at a terabit in the access network by 2040."

Whether anyone will actually need those kinds of speeds is a big question. Chapman and others who spoke here last week acknowledged that few, if any, residential customers need 1-Gig speeds today, but competition demands it.

"Technology permits, competition drives it, and the market accepts," Chapman said.

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And that's the path the industry is traveling as supply continues to outpace demand.

"You can't be a serious operator today if you don't have a gigabit tier in your portfolio," Chapman said. "I offer to you that people don't buy speed because they need it, but because they can."  

DOCSIS will live on

Chapman acknowledges that such lofty, future speeds will be delivered on fiber-to-the-premises (FTTP) networks, but stressed that history shows that DOCSIS networks likely will be here for years to come.

He notes that DOCSIS effectively "killed" DSL in 2000 with megabit-level speeds, but didn't overtake DSL on a worldwide basis until 2020.

(Source: 'The Future of Broadband', John Chapman, March 2024)

"We [cable] killed DSL in 2000 and it's still around 20 years later. That suggests that DOCSIS is going to be around 20 years from now," Chapman said.

That also suggests that fiber and DOCSIS will coexist for a long time. "Fiber is the long-term solution. Cable is more of a nearer-term solution," he explained.

Thinking 'fiber-first'

But the road ahead also means the "cable" industry needs to alter its thinking.

The industry has reached "an inflection point between the maturity of DOCSIS and the inevitability of fiber," Chapman said. "It's about coming up with a graceful, pragmatic solution to migrate, to transition from DOCSIS to fiber. And that migration's going to take 20 years. But we need a strategy that accommodates the two."

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He said the industry would do well to shift from a DOCSIS-first/fiber-second mentality to one that is led by fiber.

"I think that little switch is the biggest problem and the biggest challenge we have. It's a cultural change," Chapman added. "If you can do that, you'll be the operators that are building and delivering that terabit service in 2040."