The Federal Communications Commission, as expected, approved a measure that would make “white space” spectrum available for wireless broadband. White space is industry lingo for the unused airwaves that abut broadcast TV spectrum, providing a buffer zone from stray signals and other inferference. The buffer zone was set up more than 50 years ago when TV was first invented. The FCC’s white-space plan was initially proposed four years ago. More than 25,000 comments — from supporters as well as critics — were submitted.