Comcast pushes 4-gig DOCSIS 4.0 link live for Philly biz customer

Comcast is closing the year by planting a DOCSIS 4.0 flag in Philadelphia, turning up a symmetrical multi-gig connection for a business customer on its live network in the city. As Comcast gears up for widespread deployments in the second half of 2023, Chief Network Officer Elad Nafshi told Fierce the operator’s next steps will focus on hardening its full duplex (FDX) technology and figuring out how to scale from one connection to millions.

Back in September, Comcast delivered speeds of 6 Gbps downstream and 4 Gbps upstream in an FDX demonstration using a six-amplifier cascade. While amplifiers will be key to Comcast’s broader deployment, Nafshi said none were used in its latest trial in Philadelphia given they’re still in development. He added the trial achieved symmetrical speeds of 4 Gbps, but noted speed was not necessarily the focus of its test.

“This is showcasing the fact that this is getting ready for prime time,” he said. “The speed [question] is just how do we operationalize the modulation of the delivery after the path is set. I’m more excited right now about just being able to put that on a live plant and have that comingle, interface with everything else that we have. That really validates that DOCSIS 4.0 can coexist on the existing network with everything else that we have, the video channels, the DOCSIS 3.0, DOCSIS 3.1, et cetera.”

Nafshi said the trial allowed it to test several different DOCSIS 4.0 modems. Asked who it is working with, he said it is continuing an existing partnership with Technicolor.

Next steps

The CNO said Comcast remains committed to achieving broad deployments of DOCSIS 4.0 in the second half of 2023. So, its work over the next several months will focus on how to add amplifiers in the field, hardening that equipment and putting the operational pieces together so it can smoothly add, operate and maintain multi-gig services going forward. And, of course, it will also have an eye toward increasing the multi-gig speeds available. It currently has an asymmetrical DOCSIS 3.1 product offering 2 Gbps down and up to 200 Mbps upstream.

Comcast has set a goal to reach 56 million locations with multi-gig service by the end of 2025. Nafshi explained that the DOCSIS 4.0 rollout will be an overlay on top of that upgrade, and he expanded on a comment he made in November that Comcast expects to be able to get there with a less than $200 cost per passing.

“Not all of it is incremental because many of those homes would have required capacity augmentations just by normal operations. The net incremental cost is actually much lower than that. So, the $200 is a gross number, not a net number," he concluded.