Image source: Getty ImagesLast year, Comcast (NASDAQ: CMCSA) sparked speculation that it was working on a wireless service. It entered as a bidder in the FCC's incentive auction for wireless spectrum, and it activated an agreement to use Verizon's (NYSE: VZ) wireless network in its own service. CEO Brian Roberts finally confirmed the company's plans at Goldman Sachs' 25th annual Communacopia conference."The team of 150 people today are getting ready next year ...