Time Warner Cable will launch its WiMAX mobile broadband offering on Dec. 1 as an MNVO on the Clearwire Corp. network.

The 6mbps (downlink) service, branded as Road Runner Mobile, will initially be available in the Charlotte, Greensboro and Raleigh, N.C., markets. Dallas will follow by the end of the year, with Honolulu and Maui to come online in early 2010.

Time Warner is marketing this as a data service, launching initially with two wireless cards, one WiMAX-only and one dual-mode 3G/WiMAX, which will use the Sprint-Nextel Corp. network for the 3G portion. Sprint owns a 51 percent stake in Clearwire.

The data-centric strategy makes sense; cablecos in general are striving to make their home broadband service that much stickier and that much more competitive by offering a way to let subscribers take it with them on the go. Many cablecos (and LECs for that matter) are doing that via Wi-Fi, but WiMAX is gaining steam with Clearwire supporters. For instance, fellow Clearwire investor cableco Comcast Corp. is reselling Clearwire as the data-only High-Speed 2go service in Atlanta, Portland and Salem, Ore., and Bellingham, Wash.

“Giving our customers the convenience of mobility and the speed of 4G, Road Runner Mobile lets customers take their favorite Internet service wherever they go,” Carol Hevey, executive vice president of Time Warner Cable’s Carolina region, said in a statement. “This is an important part of our strategy to give our customers any content, on any device, anytime, anywhere.”

The MVNO strategy is key to Clearwire’s overall business plan to drive additional traffic on its fledgling 4G network in order to ramp up subscribers and monetization quickly. And of course, the greater the number of users, the more attractive of a market WiMAX becomes for consumer electronics manufacturers to create devices with WiMAX embedded.