DOCSIS 3.1 Is Right on Schedule

The unexpected popularity of 1Gbit/s broadband from Google and the biggest telcos is making cable operators keen to get D3.1 deployed so they can compete with their own gigabit services.

Brian Santo, Senior editor, Test & Measurement / Components, Light Reading

September 24, 2015

7 Min Read
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LOUISVILLE, Colo. -- Earlier this week CableLabs demonstrated that development work on DOCSIS 3.1 technology is progressing right on schedule. Cable companies should have D3.1 installations up and running in early 2016.

Some notes from the CableLabs interop: There were a couple of new products publicly demonstrated for the first time during the demos, and test and measurement (T&M) companies were given a surprising yet thoroughly deserved co-starring role at the event. Representatives from Broadcom Corp. (Nasdaq: BRCM) said the company's new D3.1 chipset -- eagerly awaited by nearly everyone making D3.1 equipment -- will be moving into full production in a few weeks, which was slightly more temporal specificity than previously available.

Also, CableLabs said it has added a new procedure meant to aid the process of getting DOCSIS products ready for market. The organization certifies cable modems (CM) and qualifies cable modem termination systems (CMTS). In June it began a new "dry run" program that helps vendors prepare their products to be submitted for certification/qualification. (CableLabs is just now wrapping a cert wave; it will announce the results in the near future.)

Getting demonstrative
At the event, the organization set up several different demonstrations, each showing the status of a different characteristic of the new cable transmission standard. One demo illustrated that improvements in the spectral efficiency of D3.1 technology over D3.0 will be much closer to the high end of the projected range (25%-50%); one showed that the broadband speeds MSOs will be able to offer right off the bat could exceed 4.5 Gbit/s; yet another demonstrated that D3.1 is fully backward-compatible with D3.0.

The spectral efficiency and backwards-compatibility were originally thought to be among D3.1's most salient benefits; an operator could implement DOCSIS 3.1 technology in stages, mixing and matching D3.0 and D3.1 technology as needed, to gradually liberate spectrum which could then be used for other purposes -- adding TV channels, for example, or clearing space for 4K content. A closely associated benefit is the reduction in cost per bit, which will help minimize operating costs.

The ability to bond enough channels to offer any individual customer broadband service at 1 Gbit/s (and eventually up to at least 10 Gbit/s) is another key benefit, but who needs a gigabit coming into their homes? Not many people today.

Google Fiber Inc. made "need" irrelevant in 2012 when it started offering gigabit service for $70 a month, however. Now gigabit is all about "want." For $70? Hey, why not? Verizon Communications Inc. (NYSE: VZ), AT&T Gigapower , and CenturyLink Inc. (NYSE: CTL) followed suit with fiber-based gigabit services. Meanwhile, cable companies relying on the current 3.0 iteration of DOCSIS have been able to counter with a maximum of about 300 Mbit/s.

Want to know more about the impact of web services on the pay-TV sector? Check out our dedicated OTT services content channel here on Light Reading.

So any cable operator up against either Google or a telco with fiber now has a keen interest in offering gigabit services.

Comcast Corp. (Nasdaq: CMCSA, CMCSK) is champing at the bit to offer realistic gigabit services as soon as it can. The company's Gigabit Pro service announced earlier this year is not price competitive at all, and includes an installation process that is ridiculous in terms of both complexity and cost; the service is a marketing stopgap at best. (See Comcast trots out Gigabit Pro… at a price.)

Comcast CTO Tony Werner reiterated his company's intention to start deploying DOCSIS 3.1 as soon as it becomes available. After that, he would say only that he's pleased with the progress the industry is making with D3.1. "There are a lot of things I lose sleep over," he told reporters. "I'm not losing any sleep over this. It's going to work, and it's going to work as advertised."

Each of the several demos was centered on a CMTS paired with a set of different cable modems, along with the T&M equipment necessary to prove that the CMTS/CM combinations were doing what they were supposed to be doing.

Arris Group Inc. (Nasdaq: ARRS), Casa Systems Inc. , Cisco Systems Inc. (Nasdaq: CSCO) and Huawei Technologies Co. Ltd. had demos built around their CMTSs. Casa CEO Jerry Guo pointed out that the Casa CMTS was running the company's new DS8x192 board, introduced at the end of August.

Huawei's was the only one to anchor more than one demo. The company proudly proclaimed it is first to deliver a system using OFDMA on the upstream, and the only CMTS vendor to be performing DOCSIS 3.1 registration. [Note: Casa says it too has implemented OFDMA on the upstream; it just didn't demonstrate it on Monday.]

Huawei engineers were clearly hoping this demonstration of technological prowess would establish the company's bona fides and catch the attention of North American MSOs, who have yet to be seen in public doing so much as giving Huawei the time of day. TDC in Denmark is the only cable operator known to be testing Huawei's CMTS.

Cable modems involved in the various demonstrations included models from (in no particular order) Askey, Castlenet, Humax, Technicolor (both its own and Comcast’s Xfinity), Sagem, Netgear, Pace, and Ubee.

Technicolor (Euronext Paris: TCH; NYSE: TCH) touted a model with a diplex switch that would allow it to operate on plants that are split at either the current 42MHz or at the so-called mid-split of 85MHz.

Humax Co. Ltd. showed a voice-activated, MoCA-based model that can be used on plants with the 85MHz split. The Humax CM featured 4x4 WiFi, but an 8x8 model is due next year.

Not part of the demos but being passed around for inspection was a cable modem mock-up from Intel Corp. (Nasdaq: INTC) that was significantly smaller than the average CM -- roughly the size of an Apple TV puck, housed in Intel-blue plastic.

Next page: A walk on the T&M side

A walk on the T&M side
Viavi Solutions Inc. showed off the latest version of its OneExpert signal analyzers, the ONX-580, which is capable of characterizing both MPEG and OFDM streams. The company said the model on display was its first to incorporate a DOCSIS 3.1 chipset (the chipsets have been available from Broadcom in sample amounts for several months).

Comsonics showed a tester that ordinarily would be used for leakage detection but has been repurposed to detect potential interference from LTE-U.

Averna 's DP-1000 DOCSIS tester, typically used for qualification/certification, was being used for one demo.

Trilithic Inc. was showing a D3.1 field tester capable of characterizing PLCs (physical layer link channels). The company will soon be commercially offering a firmware upgrade, followed by a hardware upgrade with a D3.1 chipset built in. The idea is to get a tester with enough baseline capabilities to enable field technicians to validate D3.1 deployments.

Keysite Technologies was doing signal analysis using its 86900 software to characterize the OFDM signals. OFDM is a modulation scheme common to WiFi and cellular communications, but new to cable as part of DOCSIS 3.1. The characterization challenge, Keysight representatives said, is that in D3.1, OFDM bit densities are far, far denser than in any other applications.

FutureWei 's Jack Moran, showing off a distributed CCAP system from Huawei, endorsed the Rohde & Schwarz GmbH & Co. KG tester being used to show a constellation diagram. "The only thing that can analyze it is a Rohde & Schwarz signal analyzer," Moran said.

— Brian Santo, Senior Editor, Components, T&M, Light Reading

About the Author

Brian Santo

Senior editor, Test & Measurement / Components, Light Reading

Santo joined Light Reading on September 14, 2015, with a mission to turn the test & measurement and components sectors upside down and then see what falls out, photograph the debris and then write about it in a manner befitting his vast experience. That experience includes more than nine years at video and broadband industry publication CED, where he was editor-in-chief until May 2015. He previously worked as an analyst at SNL Kagan, as Technology Editor of Cable World and held various editorial roles at Electronic Engineering Times, IEEE Spectrum and Electronic News. Santo has also made and sold bedroom furniture, which is not directly relevant to his role at Light Reading but which has already earned him the nickname 'Cribmaster.'

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