The Federal Communications Commission approved a proposal on Thursday that would open vast amounts of unused broadcast television airwaves (known as “white space”) for high-speed wireless broadband networks and other unlicensed applications, the first significant block of spectrum made available for unlicensed use by the F.C.C. in 20 years.

The new order eliminates a requirement that devices scan the airwaves for available signals. Rather, they can rely on a database of digital signals, updated daily, for use in locating an available channel on which to transmit.

Supporters of the measure hope the airwaves will be used for stronger and faster wireless networks — known as “super Wi-Fi” because of the signals’ ability to pass more easily through obstacles — and for use in providing Internet access to rural areas.