The cable industry is a business predicated on serving homes. Though the telephone industry has, of course, a huge century-old beach head in the home in the form of legacy voice services, cable multiple service operators (MSOs) have built a great industry. They still dominate entertainment video -- though that dominance is fraying a bit around the edges -- and enjoy a slight advantage in broadband over their telco competitors. All in all, cable is the king of its castle.

Cable hasn’t done as well, however, when it went through the front door. It traditionally has lacked a robust wireless adjunct. The industry tried a variety of things over the years, but hasn’t been able to put together a wireless option able to meaningfully challenge the entrenched cellular carriers.

That background is useful in assessing the news that Comcast's previously promised rollout of Clearwire WiMax service in cooperation with WiMax co-owner Sprint-Nextel in Portland, Ore. is set for next week. Big cable operators -- Time Warner Cable and Bright House in addition to Comcast -- made a bet on WiMax in the form of Clearwire investments. It is moving on that investment as Clearwire, which is up and running publicly in Portland and Atlanta, hits full rollout stride. Clearwire says Clear is set for rollouts in six or seven more cities this year and will be well on its way to a national presence by the end of next.

Comcast plans two versions of the service, which will be offered through wireless data cards. Comcast High-Speed 2go Metro will be 4G only, while High-Speed 2go Nationwide will agilely toggle between WiMax and Sprint’s 3G network. CRN offers pricing and other details about the service, which will eventually be offered throughout the Clear network.

The cable industry’s move into wireless will begin to pick up considerable steam. Look for the other Clearwire cable partners to do the same thing, more or less, that Comcast has done. Other operators – such as Cablevision, which is saturating its New York City metro footprint with a Wi-Fi cloud – will get more deeply involved. The advent of wireless Internet protocol (IP)-based networks capable of carrying advanced services meant that it was only a matter of time before cable operators were able to shake off their agoraphobic tendencies. That time has come.