United States - Unlicensed mobile devices unlikely for next few years
According to the Federal Communications Commission (FCC), unlicensed mobile devices will not be able to make use of the white spaces between television channels for the next several years due to technical challenges that have yet to be resolved.
In addition, the makers of the unlicensed mobile devices will need to know what frequencies broadcasters will use following the completion of the so-called incentive auctions for inclusion in their chips. These incentive auctions will use frequencies voluntarily relinquished by broadcasters who, in turn, may need to re-locate to alternative frequencies. The FCC has called for these auctions to take place by 30 June 2014.
Source: Broadcasting & Cable