CableLabs Unleashes DOCSIS 3.1 Specs

As expected, CableLabs on Wednesday released the product specs for DOCSIS 3.1, a new platform that defines a way for cable operators to scale speeds up to 10 Gbps in the downstream and between 1 Gbps to 2 Gbps in the upstream.

CableLabs announced last week at the SCTE Cable-Tec Expo in Atlanta that the D3.1 specs would be out before the end of October.

The initial  batch of D3.1 interoperability documents, available here, cover the DOCSIS 3.1 physical layer and MULPI (MAC and Upper Layer Protocol) specs. CableLabs expects to complete the DOCSIS 3.1 networking management specs sometime in 2014, Matt Schmitt, CableLabs’ director of DOCSIS, told Multichannel News last week.

The product specs, which provide the blueprint necessary for silicon, cable modem and cable modem termination system (CMTS) vendors to start building D3.1 gear, has been on a fast track ever since CableLabs publicly disclosed plans for the specs about a year ago.

According to the baseline, minimum product specs, the first DOCSIS 3.1 modems will be hybrids that support both DOCSIS 3.1 and DOCSIS 3.0 spectrum, and will be capable of supporting up to 4 Gbps to 5 Gbps in the downstream. As reported last week, the DOCSIS 3.0 side will carry a minimum requirement of bonding 24 downstream QAM channels and 8 upstream QAM channels, alongside a DOCSIS 3.1 minimum that calls for the ability to tie in two channels/blocks orthogonal frequency-division multiplexing (OFDM) at 192MHz-wide each, and two 96MHz-wide channels for the upstream.

“To meet the demand for higher speed access and increased network efficiency, CableLabs completed the development of DOCSIS 3.1 specifications 40 percent faster than previous DOCSIS projects,” said Phil McKinney, president and chief executive officer of CableLabs, in a statement. “These specifications represent the combined work of a large consortium of cable industry stakeholders.”

MSOs and vendors have not specified any specific product launch or deployment dates, but the initial batch of DOCSIS 3.1 products is expected out be late 2014, enabling operators to start deployments sometime in 2015. CableLabs said it's prepared to facilitate interoperability testing of D3.1-facing products and to help gear makers prepare for certification and qualification "as soon as prototypes are available."

“Based on the significant contributions from our members and technology suppliers, CableLabs has developed the technology foundation for the delivery of next generation broadband services over HFC networks,” said Dan Rice, senior vice president of access network technologies at CableLabs.

DOCSIS 3.1 will implement techniques and technologies that enable cable operators to use bandwidth more efficiently by supporting higher modulations that pump more bits per hertz down the wire than what’s allowed today by DOCSIS 3.0.

Overall, DOCSIS 3.1 is expected to be about 50% more efficient than DOCSIS 3.0 partly through the use of 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.