CableLabs publishes DOCSIS spec
CableLabs promised to publish the DOCSIS 3.1 spec before October is out, and so it has. The organization just posted its DOCSIS 3.1 PHY (physical layer) and MULPI (MAC and upper layer protocol) specifications.
[On November 5, CED will host a webinar called DOCSIS 3.1: Plans & Strategies, with several of the contributors to the development of the specification: Comcast’s Jorge Salinger, Cox Communications’ Jeff Finkelstein, Cisco’s John Chapman, and Arris’ Ayham Al-Banna. Register here.]
Representatives of CableLabs announced at Cable-Tec Expo last week that the spec was close to finished. (Video highlights from the DOCSIS 3.1 Symposium at Cable-Tec Expo).
Two more elements of D3.1 are still forthcoming: the Operations Support System Interface for cable modems (CM), and a similar interface for cable modem termination systems (CMTS).
DOCSIS 3.1 is the technological underpinning of the cable industry’s roadmap for providing competitive IP-based services for the next 10 to 20 years. It provides for an expansion of capabilities and features in the IP portion of cable operators’ networks. They include:
- Support for up to 10 Gbps downstream and up to 1 Gbps upstream network capabilities.
- Active Queue Management to significantly reduce network delay as data traffic grows in the home network, improving responsiveness for applications such as online gaming.
- An increase in network capacity with the ability to transmit up to 50 percent more data over the same spectrum on existing HFC networks.
- Enhancements to the DOCSIS protocols will increase cable modem energy efficiency.
- DOCSIS 3.1 modems are designed to co-exist with older versions enabling incremental deployment based on market demand.
“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. “These specifications represent the combined work of a large consortium of cable industry stakeholders.”
“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.
In developing the DOCSIS 3.1 technology, CableLabs streamlined its specification development process to allow both silicon and product vendors to accelerate development and testing. The development of the specs took about a year and a half, by far the fastest development of any step to a next generation of DOCSIS technology.
One of the reasons that the cable operator industry was able to pull off the fifth iteration of DOCSIS so quickly was the choice to use existing technologies from other fields.
DOCSIS 3.1 features a new modulation scheme, along with a more sophisticated forward error correction (FEC). DOCSIS 3.1 will rely on orthogonal frequency division multiplexing (OFDM), used in DSL, LTE, Wi-Fi and MoCA, among other technologies. It will also replace the commonly used Reed-Solomon FEC with far more efficient low-density parity check (LDPC) codes.
As soon as prototypes are available, CableLabs said, it will facilitate interoperability testing of products at its labs to help equipment manufacturers prepare for certification and qualification.
The full specifications are available for download.