Enlarge / Picture of a Comcast router/modem gateway from the corporate’s web site.

Comcast right this moment provided the most recent trace of a future wherein its cable prospects will not be restricted to 35Mbps add speeds. Announcing a latest lab take a look at, Comcast mentioned its analysis workforce “deliver[ed] upstream and downstream throughputs of greater than 4Gbps” and that “future optimization” will permit “even greater capacity.”

This was “the first-ever live lab test” of a Broadcom “system-on-chip (SOC) device that will pave the way for Comcast to deliver multigigabit upload and download speeds over its hybrid-fiber coaxial (HFC) network,” Comcast mentioned. It will not require set up of extra cables as a result of the “technology works using the same types of connections already installed in hundreds of millions of homes worldwide,” Comcast mentioned.

Cable prospects have been ready a very long time for add speeds that are not a tiny fraction of obtain speeds. Comcast’s cable uploads, starting from 3Mbps to 35Mbps, are so low that Comcast hides them deep inside its on-line ordering system. While cable obtain speeds of as much as 1.2Gbps are prominently displayed, Comcast would not inform prospects what add speeds they’re going to get till they enter a legitimate bank card quantity.

Comcast justified its tactic of hiding add speeds by saying that its “website reflects the way customers use the Internet, with downstream overwhelmingly dominating usage.” But often, reminiscent of in right this moment’s announcement, Comcast acknowledges that prospects need increased add speeds.

“This milestone is particularly exciting because this technology is an important step forward toward unlocking multigigabit upload and download speeds for hundreds of millions of people worldwide, not just a select few,” Comcast govt Charlie Herrin mentioned within the announcement.

“Full duplex” DOCSIS

Comcast does provide a residential fiber service with add and obtain speeds of 2Gbps, however availability is proscribed and the service prices $300 a month, plus set up and activation prices of as much as $1,000 mixed. The fiber service requires the set up of latest wires into every house, however the newly introduced lab take a look at delivered multi-gigabit add and obtain speeds over the usual cable wires that Comcast has put in all through its 39-state territory.

The take a look at used a Broadcom SOC powered by the most recent model of DOCSIS, the Data Over Cable Service Interface Specification. The Broadcom “device is expected to become the world’s first production silicon to be developed using the DOCSIS 4.0 Full Duplex standard, which represents an evolutionary leap forward in the ability to deliver ultra-fast speeds over HFC [hybrid fiber-coaxial] networks,” Comcast mentioned. “One of the most important breakthroughs in the DOCSIS 4.0 standard is the ability to use network spectrum more efficiently, allowing operators to dramatically increase upstream speeds without sacrificing downstream spectrum to do so.”

Years of unfulfilled upload-speed guarantees

The cable {industry} has been promising symmetrical add and obtain speeds over cable networks for years with out ever saying when such speeds will grow to be accessible.

The DOCSIS 3.1 specification launched in 2013 theoretically allowed 10Gbps downloads and 1Gbps add speeds, however precise implementations by no means got here near these numbers. An replace to DOCSIS 3.1 finalized late in 2017 was presupposed to deliver obtain and add speeds of 10Gbps, and the cable {industry} unveiled a “10G” advertising marketing campaign in January 2019 to boast of these symmetrical 10Gbps speeds. Comcast right this moment referred to as its latest take a look at “an important step forward on the path to 10G.”

The full-duplex model of DOCSIS 3.1 was up to date and renamed “DOCSIS 4.0.” Despite the “full duplex” identify, the cable {industry} has lowered the estimated upstream speeds from 10Gbps to 6Gbps.

“Current DOCSIS 3.1 cable modems support capacities up to 5Gbps downstream and 1.5Gbps upstream,” the cable-industry group CableLabs says. “DOCSIS 4.0 cable modems will support capacities up to 10Gbps downstream and 6Gbps upstream.”

Comcast mentioned {that a} “key advantage of DOCSIS 4.0 Full Duplex is that it establishes a foundation for operators to deliver multigigabit speeds over their existing networks to the connections already in hundreds of millions of homes around the world, without the need for massive digging and construction projects.” Comcast referred to as it “a powerful new tool to support our mission of delivering the best possible connected experiences to our customers,” nevertheless it did not say when these prospects will be capable to purchase a future “full duplex” service.

Smaller add improve presumably on faucet

Comcast in October 2020 mentioned it achieved a “technical milestone” that delivered 1.25Gbps obtain and add speeds over present cable wires throughout testing at a house in Jacksonville, Florida. While gigabit add speeds over cable can be an enormous enchancment, it seemingly is not wherever near being carried out. It’s additionally not clear when Comcast will elevate cable add speeds to something increased than 35Mbps—Comcast hasn’t even confirmed a rise to 50Mbps uploads, which is already provided by WOW on that firm’s gigabit-download plan.

Currently, Comcast’s 25Mbps obtain plan comes with 3Mbps uploads; the 100Mbps and 200Mbps obtain plans each have 5Mbps uploads; the 400Mbps obtain plan has 10Mbps uploads; the 800Mbps plan has 15Mbps uploads; and the 1Gbps obtain plan (1.2Gbps in some areas) comes with 35Mbps uploads. By distinction, fiber-to-the-home suppliers usually present symmetrical add and obtain speeds of as much as 1Gbps.

Comcast did trace at increased add speeds “in the near term” utilizing DOCSIS 3.1, nevertheless it did not specify what these speeds can be or say when they are going to be accessible:

Even as Comcast works to check and deploy Full Duplex DOCSIS to allow multigigabit add and obtain speeds sooner or later, the corporate is leveraging the applied sciences from the October trial, together with DOCSIS 3.1 within the upstream, to extend velocity and capability within the close to time period.

The October 2020 take a look at “deliver[ed] 1.25 Gig symmetrical speeds over a live, all-digital network by leveraging advances in Distributed Access Architecture, Remote PHY digital nodes, and a cloud-based virtualized cable modem termination system platform,” Comcast mentioned. In the newer take a look at introduced right this moment, the demonstration occurred in a “simulated” surroundings as a substitute of a house.

“Comcast technologists in Philadelphia and Denver conducted the test by installing the Broadcom SOC in a simulated network environment to track the performance of its Full Duplex DOCSIS features—including echo cancellation and overlapping spectrum—which combine to support substantial improvements in network throughput,” Comcast mentioned.

Source arstechnica.com