Cable Preps for DOCSIS 3.1 Debut

As Gigabit Fever continues to sweep the land, CableLabs is scrambling to start certifying new DOCSIS 3.1 equipment for the cable industry's use as early as next spring.

Expressly designed for the coming Gigabit Era, DOCSIS 3.1 promises to enable cable operators to deliver downstream data speeds as high as 10 Gbit/s and upstream speeds of 1 Gbit/s or more. Drafted in record time, the spec was completed late last year, and could make its debut on North American and European cable systems as soon as next summer or fall.

Senior technologists from CableLabs , Comcast Corp. (Nasdaq: CMCSA, CMCSK), Cisco Systems Inc. (Nasdaq: CSCO) and elsewhere in the cable sector stressed the urgency of refining and deploying cable's next-gen broadband standard as quickly as possible during several forums at the Society of Cable Telecommunications Engineers (SCTE) Cable-Tec Expo show in Denver last week. They said CableLabs plans to begin formal certification testing of DOCSIS 3.1 cable modems and broadband gateways in the second quarter of 2015, after some earlier lab trials beginning at the end of this year.

Speaking at a show breakfast hosted by BTR, CableLabs CTO Ralph Brown said the industry R&D group is now putting the finishing touches on its testing plans for the latest DOCSIS spec. Pointing to the numerous DOCSIS 3.1 equipment prototypes on the exhibit floor, Brown said the new spec is still proceeding on schedule. (See Arris Preps First Live DOCSIS 3.1 Demo.)

At a pre-show symposium on DOCSIS 3.1, Belal Hamzeh, director of network technologies for CableLabs, outlined the standards group's testing plans. Hamzeh said the first "plugfests" and equipment interoperability tests should begin in December, followed by more formal product certifications and qualification testing in the second quarter of 2015. “So far, we are on target, and the vendors are moving ahead" with products, he said.

Speaking at the same symposium, Jorge Salinger, vice president of access architecture for Comcast, stressed that much of the preparatory work for the new DOCSIS 3.1 products has already been completed. For example, he noted, at least three major chipmakers – Broadcom Corp. (Nasdaq: BRCM), Intel Corp. (Nasdaq: INTC) and STMicroelectronics NV (NYSE: STM) – are already putting together the silicon for 3.1 gear.

Salinger also stressed that cable vendors and operators are racing to bring the new spec to market in record time. "There hasn’t been any DOCSIS spec that was conceived and developed so fast" as DOCSIS 3.1, he said, predicting that it will take the industry even less time to start deploying DOCSIS 3.1 gear than it took to write the new specs. "DOCSIS 3.1 is being developed very, very fast."

For its part, Comcast aims to start DOCSIS 3.1 trials as soon as the equipment becomes available, Salinger said. That suggests that the large MSO could begin testing new modems and gateways on its plant in the second half of next year.

Salinger said Comcast is already preparing for these tests by working on the "operational readiness" of its plant. For one thing, the MSO is seeking to improve the critical signal-to-noise ratio (SNR) throughout its network to clear more spectrum for DOCSIS channels. For another, Comcast is moving to swap out its MPEG-2 HD set-top boxes for more efficient MPEG-4 HD boxes, which will give it more capacity as well.

Get the latest updates on cable's new DOCSIS 3.1 spec by visiting Light Reading's DOCSIS content channel.

As was the case with cable's current flagship broadband spec, DOCSIS 3.0, the industry will most likely deploy new 3.1 products for the downstream path first, followed by products for the upstream side somewhat later. That's in large part due to perceived consumer demand and the growing competition with such rivals as Google Fiber Inc. , AT&T Inc. (NYSE: T), CenturyLink Inc. (NYSE: CTL) and the like, which has fueled the emerging Gigabit Cities movement.

Salinger said he "doesn't expect a big price delta" between the older DOCSIS 3.0 modems and the new DOCSIS 3.1 modems, which will be "backward compatible" to support both the DOCSIS 3.0 and DOCSIS 3.1 platforms. "It will be a long time before we don’t have any DOCSIS 3.0 modems in the network,” he said, noting that about half of Comcast’s deployed modems are now DOCSIS 3.0 devices, and the other half are DOCSIS 2.0. This approach, he said, should enable cable operators to seed the market with DOCSIS 3.1-capable modems before they upgrade to DOCSIS 3.1 spectrum, allowing for a smoother, more gradual transition.

Despite the higher speeds that Google Fiber, AT&T and other rivals are now rolling out with the help of all-fiber, or at least fiber-rich, networks, Salinger and other cable technologists insisted that cable's hybrid fiber/coax (HFC) networks still have the chops to keep their rivals at bay. "The [new cable] technology is maturing and stabilizing," said John Chapman, CTO of Cisco's Cable Access Business Unit and a Cisco Fellow. At most, he predicted, "We'll likely see a blending of fiber and DOCSIS technologies" over the next few years.

Salinger came down even stronger in cable's favor: "The apples in the tree are getting higher and higher, but there's still room for growth," he said. "There isn't anything we cannot do with HFC networks that we can do with fiber."

— Alan Breznick, Cable/Video Practice Leader, Light Reading

JediMastaDJ 3/13/2015 | 9:13:58 AM
Re: Shared? No, that is the max speed at the device. Comcast is pushing for 1 Gbps by the end of this year in all markets using the new DOCSIS 3.1 standard.
Lv99_Slacker 11/29/2014 | 2:06:59 AM
"The 1Gbit Revolution" Thank you, based Google, for ushering the country into a new era.
KBode 10/1/2014 | 8:02:47 AM
Shared? I keep forgetting, is that 10 Gbps down, 1 Gbps up shared per node? I think companies like CenturyLink and AT&T, already struggling to keep pace with existing DOCSIS 3.0 technologies, aren't going to be very happy when this technology starts arriving en masse in 2016. They've barely been able (willing) to invest in upgrades to match cable speeds as it is.
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