Waiting On Wideband Gear


Headend equipment that promises to let cable companies offer Internet access at 100 Megabits per second — and higher — has passed the cut on the first go-round.

But the applause surrounding this development may have sounded like one hand clapping: The modems that are needed on the other end of the coax didn’t make the grade.

CableLabs said Dec. 19 that it awarded qualification status for Data Over Cable Service Interface Specification (DOCSIS) 3.0 headend gear from Arris, Casa Systems and Cisco Systems.

While that’s a notable achievement for a new CableLabs specification, it’s only half the equation.

Cable modems submitted for testing by Arris and Motorola did not pass certification. That means those vendors will need to correct any aspects of their DOCSIS 3.0 modems that didn’t meet the spec and submit their products for retesting in early 2008.

CableLabs, as is customary, declined to say what the deficiencies were in the cable modems. CEO Dick Green, as part of last month’s announcement, said he was “very encouraged by the progress made toward certification of cable modems, particularly with the performance of the hardware.”

The lack of approved DOCSIS 3.0 cable modems didn’t prevent Comcast chairman and CEO Brian Roberts from praising the CMTS certifications.

Roberts, who is also chairman of CableLabs, called the initial qualifications “a great step for our industry.”

The “rapid certification” of DOCSIS 3.0, Roberts said in the CableLabs-issued press release, “will enable companies to begin to develop products that will support the rapid deployment of DOCSIS 3.0 services in 2008.”

Comcast has been particularly vocal about deploying the technology. Roberts himself demonstrated a “wideband” modem, supplied by Arris, at the 2007 Cable Show. Comcast has said it expects to have DOCSIS 3.0 available to 20% of its homes passed by the end of 2008.

The next-generation broadband technology will be critical for Comcast and other operators to compete with the high-speed Internet services offered by some telephone providers. Chiefly, that’s been Verizon Communications, which is marketing FiOS Internet service at 50 Mbps in six states.

DOCSIS 3.0 enables downstream data rates of 160 Megabits per second or higher and upstream data rates of 120 Mbps or higher by “bonding” together multiple 6-Megahertz channels in a cable system. The specification provides many other features and improvements to DOCSIS 2.0, including more advanced security, but the most tantalizing one is the higher bandwidth.

The headend CMTSs from Arris, Casa and Cisco were tested in CableLabs’ Certification Wave 56 under a tiered program that was created to encourage vendors to submit gear for testing earlier than they otherwise might have.

Under the tiered certification program, Casa’s DOCSIS 3.0 cable-modem termination system received “silver” qualification, meaning it provides both upstream and downstream channel bonding. Arris and Cisco received “bronze” qualification for CMTS headend gear, meaning their products provide downstream channel bonding.

CableLabs said full DOCSIS 3.0 compliance ultimately will be the sole certification level for CMTS vendors, with the two lower levels of qualification to be phased out.

While Motorola didn’t submit its DOCSIS 3.0 CMTS for the most recent CableLabs certification wave, the company in December announced two customers for its channel-bonding cable modem termination system: C&M and CJ CableNet, two of the largest cable operators in South Korea. The two operators are using the Motorola BSR 64000 CMTS and SurfBoard cable modems, and both planned to begin offering broadband service with 100-Mbps Internet downloads to their subscribers before the end of 2007.

Spec'ing Out DOCSIS
A timeline of 10 years of cable modems: 


First Released

Key Features


March 1998*

Basic broadband Internet connectivity, including ability to rate-limit a particular subscriber’s data


April 1999

Improves operational flexibility, security and quality-of-service features


January 2002

Improves upstream reliability and throughput for symmetric services


August 2006

Provides channel bonding for minimum 160 Mbps downstream, support for IPv6 and multicast for IPTV applications

The lack of CableLabs’ seal of approval did not deter C&M and CJ CableNet from rolling out Motorola’s DOCSIS 3.0 solution. “The investments we’re making in hardware now will continue to pay off as we begin our migration to a full DOCSIS 3.0 environment,” C&M chief technology officer J.W. Koh said in a statement.

Operators in certain Asian markets are facing particularly aggressive broadband competition with 100-Mbps offerings from telcos, and have felt a more urgent need to get their hands on the channel-bonding capabilities than perhaps their North American kin.