CableLabs Eyes Month’s End As DOCSIS 3.1 Delivery Date


ATLANTA — DOCSIS 3.1 is being designed to deliver some seriously scary data speeds, so perhaps it’s only fitting that CableLabs expects to issue the product specifications by Halloween.

The core product-interface specifications — which will provide silicon makers and cable modem and cable-modem termination system vendors with the blueprint they need to start building products — will be released by the end of October, Matthew Schmitt, CableLabs’s director, DOCSIS, said here at a day-long DOCSIS 3.1 Engineering Pre-Conference Symposium ahead of SCTE Cable- Tec Expo 2013.

In a separate interview, Schmitt said the DOCSIS 3.1 networking management specs should be complete sometime in 2014.

The publication of the interface specs will essentially beat the end-of-2013 deadline set by CableLabs last year, when it unveiled the plan for DOCSIS 3.1, a platform that will scale up to 10 Gigabits per second downstream and between 1 Gbps to 2 Gbps upstream.


“It’s been a whole, industry-wide effort,” Schmitt said. The teams associated with the project “have been busting their tails” to meet the deadline.

DOCSIS 3.1 is expected to be about 50% more efficient than DOCSIS 3.0, partly through the use of orthogonal frequency-division multiplexing (OFDM), a technique that will enable operators to pack tiny subcarriers into wide blocks of bandwidth and utilize higher levels of modulation.

DOCSIS 3.1 will also support low-density parity check (LDPC), a Forward Error Correction (FEC) scheme that uses less bandwidth than the current Reed-Solomon approach.

The initial wave of DOCSIS 3.1 modems will be hybrids that support DOCSIS 3.1 and DOCSIS 3.0 spectrum. The DOCSIS 3.0 side will carry a minimum bonding requirement of 24 downstream QAM channels and 8 upstream QAM channels, alongside a 3.1 minimum that calls for two channels of OFDM at 192-Megahertz wide each, and two 96 MHz-wide upstream channels.

Operators will later decide how and when to turn up that capacity. But, when fully loaded, those 3.0/3.1 combo modems will support maximum speeds of 4 Gbps to 5 Gbps downstream and 1.5 Gbps in the upstream out of the chute.

Considering that cable operators have yet to introduce high-speed Internet tiers that advertise anything beyond 500 Megabits per second downstream using DOCSIS 3.0, the first batch of hybrid gear should have plenty of legs.

Presuming things proceed at the expected pace, those modems should start to show up by late 2014, enabling operators to start deployments in 2015.

While 3.1 will set a path to multi-Gigabit speeds, the goal isn’t to suddenly turn all of cable’s spectrum into IP and start pumping 10 Gbps to the home. The aim is to migrate to those speeds over time, so cable operators can start extracting more value out of their existing spectrum than can be squeezed out of DOCSIS 3.0 today.

“DOCSIS 3.1 is about spectrum efficiency. It’s the No. 1 goal,” Jorge Salinger, vice president, access architecture for Comcast Cable, said during a follow-up session with cable operators.


The precise launch timing of DOCSIS 3.1 isn’t set, but MSOs will welcome DOCSIS 3.1-based equipment with open arms as soon as it becomes available. “Anything we can do to expedite the readiness of 3.1 product, whether with CPE [consumer-premises equipment] or head-end equipment, we will gladly give up lab time,” Jeff Finkelstein, executive director of strategic architecture for Cox Communications, said.

Meanwhile, DOCSIS 3.0, which can already bond enough 6-MHz-wide QAM channels to support max downstream speeds of more than 1 Gbps, has plenty of life left as 3.1 gear gets developed.

“DOCSIS 3.0 is still fairly early on in reaching its full capacity,” Howard Pfeffer, senior vice president of Time Warner Cable’s Broadband Technology Group, said.


Ahead of Cable-Tec Expo, CableLabs said it expects to deliver DOCSIS 3.1 product specs by the end of October.