Comcast Corp. (Nasdaq: CMCSA, CMCSK)'s confirmation that it will start to resell Clearwire LLC (Nasdaq: CLWR)'s mobile WiMax service in Portland, Ore., this summer leaves several important questions unanswered, particularly about its Femtocell plans.

The cable operator told The Oregonian on Friday that it will start to resell the services by the middle of this year. As our colleague Jeff Baumgartner over at Cable Digital News noted, the company hasn't laid out much detail beyond that. In fact, Comcast hasn't yet said what the service will be called, what it will charge for access, or whether it will be expanded to other planned Clearwire markets this year. (See Comcast WiMaxes Portland.)

Regular readers will recall that Comcast initially said that femtocells -- tiny base stations designed to improve coverage and data download speeds in the home -- would be part of its WiMax strategy. It is not currently clear, however, whether WiMax femtocells will be available to users as Comcast starts to resell the wireless broadband service. (See Comcast Goes for WiMax Femtocells.)

Comcast's senior VP for wireless and technology, Dave Williams, said in June 2008 that a key element of the Clearwire deal for Comcast is that 5 MHz of spectrum is set aside just for WiMax femtocell deployments. That spectrum will also be available for use by any of the consortium members, which includes Comcast, fellow cable MSOs Bright House Networks and Time Warner Cable Inc. (NYSE: TWC), as well as Google (Nasdaq: GOOG) and Intel Corp. (Nasdaq: INTC). (See Cable Plays Clearwire Card and Clearwire: We're Still on Track.)

“We’ll be pushing WiMax femtocells because we have a good customer base in the home -- we sell HDTV, VOIP, and high-speed Internet connectivity. We want to take that experience in the home and add mobility," Williams told Unstrung at the time.

Since Williams's initial comments, however, Comcast has stayed quiet on the femtocell issue.In October, however, industry sources told Unstrung that the operator was prepping WiMax femtocells for the second half of 2009. The operator was believed to have issued a request for trial (RFT) to the femtocell vendor community last fall.

This would fit -- at least in theory -- with the summer timetable to resell Clearwire services. Comcast isn't talking yet, however.The company so far hasn't responded to calls to spokespeople or an email to corporate communications.

— Dan Jones, Site Editor, Unstrung