Advantage: DOCSIS 3.0

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Las Vegas — Cable operators could roll out next-generation high-speed cable-modem technology across the entire United States for “a couple billion dollars” in just a few years, Comcast senior vice president of new-media development Steve Craddock said on a panel discussion at The Cable Show '07.

The broadband technology — Cable Television Laboratories' Data Over Cable Service Interface Specification 3.0 — will be far more economical to deploy than building fiber-to-the-home, Craddock said. He noted that Verizon Communications is spending upward of $18 billion on its FiOS fiber-optic network, which will cover just 14% of the United States.

“Cable can go deploy DOCSIS 3.0 for a couple billion dollars,” Craddock said. “We could blanket the entire U.S. footprint in a matter of years, because it's an incremental upgrade.” He joked that the cost would be the kind of money you could find “in Bill Gates' sofa cushions.”

While several billion dollars is not exactly spare change, Craddock's ballpark estimate was also meant to stand in contrast to $60 billion or so the industry spent upgrading networks since the mid-1990s.

DOCSIS 3.0 equipment will be roughly the same cost per port as 2.0 headend gear, while also providing “a tremendous amount of capability and flexibility you couldn't get before,” Craddock said.

On stage at The Cable Show last week, Comcast CEO Brian Roberts demonstrated an Arris DOCSIS 3.0 modem with sustained downstream speeds hovering around 150 Megabits per second, 25 times as fast as the operator's standard 6-Mbps offering today.

The specification's key feature to allow for higher connection speeds is channel bonding, which combines multiple channels into one bigger virtual one. Craddock said that if cable operators converted all of the spectrum in their networks to be a single DOCSIS 3.0 channel-bonded connection, the bandwidth of that link would approach 5 Gigabits per second, or twice that of Gigabit Passive Optical Network technology. “So why do I need to go dig up the streets?” he added.

Comcast hasn't specified where or when it expects to first deploy DOCSIS 3.0, but company executives have said they plan to initiate trials later this year, when equipment vendors deliver the first products built to the standard. Commercial rollouts could happen in 2008.

Originally, DOCSIS 3.0 equipment was not going to be available until 2009 or 2010. That would have been “totally too late,” Craddock said. “We'd like to get this as soon as possible.”

Comcast led the charge to push up the timetable by 12 to 15 months.

Other operators said they appreciated Comcast's efforts to accelerate DOCSIS 3.0. “We're comfortable with the timing [Comcast] outlined,” Cox Communications vice president of technology Jay Rolls said. “We're not dying for this, but we don't want to put it out too long.”

To get equipment into operators' hands sooner, CableLabs introduced two interim certification levels for DOCSIS 3.0 cable-modem termination systems, which cover subsets of the full spec. The “bronze” designation includes downstream channel bonding; “silver” adds upstream bonding; and the full specification will wrap everything together. CableLabs' certification testing is expected to begin in October.

Vendors with bronze and silver certifications will be required to comply with the full DOCSIS 3.0 specification by March 2009. Cable-modem devices, meanwhile, must comply with the full spec at the outset.

Breaking certification into three pieces was necessary because of the magnitude of the DOCSIS 3.0 specification, said Doug Semon, VP of technologies and standards for Time Warner Cable. “The move from 2.0 to 3.0 is more like from 2.0 to 5.0,” he said.

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