SANTA CLARA, Calif. -- Comcast Corp. plans to have a Docsis 3.0 infrastructure in place in about 20 percent of its footprint by the end of 2008, teeing up cable modem services capable of delivering shared Internet speeds in excess of 100 Mbit/s.

The nation's largest MSO will be 3.0-capable in one-in-five homes by the end of next year, according to Comcast Chief Technology Officer Tony Werner, the keynoter here Wednesday morning at the first CableNEXT conference.

In October, Werner said the MSO had already placed orders for Docsis 3.0 equipment, with an expectation that it would be rolled out to a "substantive portion of our footprint" next year. (See Comcast Ready to Reclaim Bandwidth.)

On Wednesday, Werner did not specify which Comcast markets would get Docsis 3.0 first, but the most likely candidates are the systems doing battle with Verizon Communications Inc. and the telco's fiber-fed FiOS Internet services. Locations for those installations could include, but won't be limited to, Reston, Va., and parts of Massachusetts.

In addition to offering faster Internet service tiers, Comcast is also looking for gear based on the new CableLabs specification to help bridge content between the Web and the television. During his presentation, Werner outlined a scenario in which new "RNG" set-top models are fed content by the operator's traditional video network and Docsis 3.0 cable modems. RNG, an acronym for Residential Network Gateway, is an "open" set-top project that will produce a family of models, including a basic, mass market device called the RNG 100, and the RNG 200, a higher-end box with built-in MPEG-4 and high-definition/digital video recorder capabilities. CableLabs recently awarded Docsis 2.0 certification to an RNG 200 model developed by Scientific Atlanta and parent company Cisco Systems Inc.. (See CableLabs Stamps New Cisco Set-Top .)

Although the full Docsis 3.0 specification calls for the bonding of at least four upstream and four downstream channels, initial Comcast deployments will be a downstream-only affair.

That's more a reflection of the status of upstream channel bonding technology than one of Comcast's Docsis 3.0 service strategy. Docsis 3.0 upstream channel bonding won't likely won't be ready for prime time until late next year or possibly 2009.

To help expedite Docsis 3.0 deployments, CableLabs introduced a tiered test program for cable modem termination system (CMTS) equipment. The "Bronze" level introduces downstream channel bonding and IPv6, while "Silver" adds in upstream channel bonding. Modems submitted for Docsis 3.0 testing must support the entire specification. (See CableLabs Accelerates Docsis 3.0 Testing .)

In the first official Docsis 3.0 test wave at CableLabs, which is presently underway, only one CMTS supplier -- Casa Systems Inc., a start-up based in Andover, Mass. -- submitted a product for "Full" CMTS testing. Arris Group Inc. and Cisco put their respective CMTS products in for Bronze testing. Every modem up for 3.0 testing in Wave 56 is powered by Texas Instruments Inc. silicon. (See Vendors Ride First Docsis 3.0 Wave .)

If downstream channel bonding becomes the focus of Docsis 3.0 trials and deployments heading into 2008, that may be welcome news for some modem suppliers, particularly those that are basing models on Broadcom Corp. chipsets.

Earlier this week, Thomson unveiled the DCM465, a "pre"-Docsis 3.0 modem with Broadcom chips that bond multiple Docsis 2.0 downstream channels. (See Thomson Markets 100-Mbit/s Modem.)

A Thomson spokeswoman said that the modem is not upgradeable to Docsis 3.0, and will be used by operators "where competitive threats are looming." It will enter field trials in the first quarter of next year. Thomson, she added, plans to introduce a full Docsis 3.0 modem -- the DCM475 -- sometime in 2008.

— Jeff Baumgartner, Site Editor, Cable Digital News