A group of technology companies led by Google won an important victory in Washington on Tuesday as the Federal Communications Commission approved a proposal to open up parts of the radio spectrum for unlicensed users.

Google had argued that the pieces of spectrum, known as “white spaces” because they act as empty “buffers” between broadcast TV signals, would stimulate a range of new wireless broadband services, in much the way the availability of unlicensed spectrum had led to widespread use of short-range WiFi networks.