CableLabs releases DOCSIS 3.1 chip specifications

CableLabs, the R&D organization that establishes specifications for U.S. cable operator networks, has released physical layer (PHY) and MAC and Upper Layer Protocol (MULPI) specifications for DOCSIS 3.1. This latest version of DOCSIS, the operating system used most commonly in U.S. cable MSO networks, promises to support 10 Gbps downstream and 1 Gbps upstream, putting it on a par with fiber to the home (FTTH) transmission capacities.

CableLabs announced it would begin work on DOCSIS 3.1 last fall at SCTE Cable-Tec Expo 2012 (see “SCTE Special Working Group to tackle DOCSIS 3.1”). “To meet the demand for higher speed access and increased network efficiency, CableLabs completed the development of DOCSIS 3.1 specifications 40% faster than previous DOCSIS projects,” said Phil McKinney, president and CEO of CableLabs, via a press release. “These specifications represent the combined work of a large consortium of cable industry stakeholders.”

While the official specifications have just now been announced, CableLabs had distributed “prerelease” versions of the specifications to systems vendors. Last week at the 2013 edition of SCTE Cable-Tec in Atlanta, Huawei showed off DOCSIS 3.1 demonstration cards using FPGAs based on these early specifications, and other vendors have moved just as swiftly. CableLabs says it will facilitate product interoperability testing to help equipment manufacturers prepare for certification and qualification. Given what was on display and discussed at the show, the market should see significant steps toward DOCSIS 3.1 products taken next year.

DOCSIS 3.1 will leverage orthogonal frequency-division multiplexing (OFDM) to enable the jump in capacity. It will be backward compatible with the QAM-based DOCSIS 3.0, in that the new specifications will enable the OFDM signals to travel alongside QAM channels over the same coax line. The spectrum savings DOCSIS 3.1 will enable should increase the data capacity of a hybrid fiber/coax network by 50%, CableLabs says.

In addition to the data rate upgrade, DOCSIS 3.1 will offer other benefits, CableLabs says. For example, the use of Active Queue Management will reduce network delay and therefore improve quality of experience, particularly for applications such as online gaming. Cable modem energy efficiency should improve as well.

The new specifications are available for download at http://www.cablelabs.com/cablemodem/specifications/specifications31.html.

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