Comcast is reportedly in the midst of testing femtocells, devices which essentially act as an indoor tower for wireless voice and data services -- allowing you to place calls over your home broadband connection. Comcast's investment deal with Clearwire included a provision that set aside 5 MHz of spectrum solely for WiMAX femtocells, but an anonymous source tells Fierce Wireless that deployment of the service won't happen until next year -- if it happens at all. Comcast of course offers re-branded Clearwire wireless broadband service as part of a new suite of bundles being offered in three markets so far. Ultimately, Clearwire and Comcast will likely deploy voice services over the Mobile WiMax network. Given the initial problems users are seeing with Clearwire signal, femtocells will likely be a necessary evolution.