The UHF spectrum, which ranges from 400 to 700 MHz, is superior to the higher-frequency signals used for existing Wi-Fi hotspots, the researchers said, as these signals carry for miles and are not blocked by walls or trees.

Source: How new ‘white space’ rules could lead to an urban super-Wi-Fi | Computerworld

It should be noted that carriers such as AT&T and related associations such as the National Association of Broadcasters objected to the FCC rules in the run up to the commission’s August meeting, citing concerns that new unlicensed uses in the 600 MHz band would create interference.

I wonder what AT&T’s true motivation for their objection.