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DOCSIS 3.1 Interops, Plugfests To Kick Off This Year: CableLabs

DENVER — CableLabs is making progress on test plans and equipment “plugfests” that will help to lead the way to product certification testing in the first half of next year and an expected initial wave of field deployments before the end of 2015.

CableLabs is developing DOCSIS 3.1 test plans now, with the first plugfests and interoperability tests slated for this December, Belal Hamzeh, the director of network technologies at CableLabs, said Sept. 22 during an SCTE Cable-Tec Expo Pre-show Symposium dedicated to DOCSIS 3.1 and WiFi developments.

Hamzeh said official certification and qualification against the DOCSIS 3.1 specs could start as early as the second quarter of 2015. “So far we are on target, and the vendors are moving ahead … with products,” Hamzeh said.

The speed of that product development is only being matched by the speeds that DOCSIS 3.1 is designed to support — up to 10 Gigabits per second downstream and at least 1 Gbps upstream.

“There hasn’t been any DOCSIS spec that was conceived and developed so fast … as DOCSIS 3.1,” Jorge Salinger, Comcast’s vice president, access architecture, said, noting that the process of initially deploying DOCSIS 3.1 will likely take less time than it took to write the specs.

Although products are currently in development, Salinger pointed out that the work around DOCSIS 3.1 is mostly done, noting that at least three chipmakers — Broadcom, Intel and STMicroelectronics — are building D3.1 silicon. But as it was with DOCSIS 3.0, the emerging platform will see products for the downstream develop faster than for the upstream side.

He also expects there to be a small cost delta between DOCSIS 3.0 modems and DOCSIS 3.1 modems, which will be hybrids that can support both DOCSIS 3.0 and DOCSIS 3.1 spectrum to ensure backward compatibility.

“It will be a long time before we don’t have any DOCSIS 3.0 modems in the network,” Salinger said, estimating that about half of Comcast’s deployed modems are DOCSIS 3.0, and the other half are DOCSIS 2.0.

That hybrid approach will allow cable operators to seed the market with D3.1-capable modems before they activate DOCSIS 3.1 spectrum, which will be more efficient (up to 50%), thanks to the introduction of orthogonal frequency-division multiplexing (OFDM) modulation and a new forward error-correction technique called low-density parity-check (LDPC).

“It’s a very smooth transition approach,” Salinger said.

Those hybrid modems, when paired with the requisite amount of spectrum, will help cable carve a path to 1-Gbps broadband services because those devices will be capable of pumping out an aggregate of about 1.7 Gbps out of the chute.

While DOCSIS 3.1 supports spectrum upgrades above 1 GHz and a wider upstream path, Salinger said operators with plant built out to 750 MHz or 860 MHz will still be in position to take advantage of the new spec.

Comcast is preparing for DOCSIS 3.1, Salinger said, but he didn’t commit to a specific rollout timeframe. “We expect to begin trials as soon as [products] become available,” he said.

If current expectations hold up, operators could start field trials by the second half of 2015.

Salinger acknowledged that the biggest obstacle to DOCSIS 3.1 isn’t the equipment, but obtaining the right tools and freeing up the spectrum necessary for the new platform.

To help free up more spectrum for D3.1, Comcast is starting to remove MPEG-2 HD boxes and swap in more efficient MPEG-4-capable HD set-tops, he said.