The transition from analog to digital broadcasts has opened up radio spectrum that could be used to deliver long-range, low-cost wireless Internet service using white spaces, which are empty fragments of the spectrum scattered between used frequencies. White space frequencies could be used to provide broadband Internet access in rural areas and fill in gaps in city Wi-Fi networks. For example, Microsoft Research's Ranveer Chandra says white space frequencies could be used to allow people to connect to their home network from up to a mile away. Last November, the Federal Communications Commission (FCC) ruled that companies could build devices that transmit over white spaces, but also required that those devices should not interfere with existing broadcasts. Microsoft researchers have designed a series of protocols, called White Fi, to account for the restrictions involved in using white spaces. Chandra says wireless networking has traditionally used an open spectrum with all users being equal shareholders, but in white spaces some users are primary users. Chandra says his research team recently received an experimental license from the FCC allowing them to build a prototype White Fi system on the Microsoft Research campus. The researchers will send their findings to the FCC in the hope that the data will help establish future white-space regulations. The blueprints for a computer network that uses white spaces were presented at ACM's SIGCOMM 2009 conference, which takes place August 17-21 in Barcelona, Spain.