More recently, wireless microphones used in theatres and other venues have been allowed to use some of these frequencies as the chances they would interfere with TV services was very small, but if wireless devices en masse start transmitting in these spaces, it's no surprise that. Much of the opposition to liberalising white space was due to TV stations' and wireless microphone users' fears of interference from unlicensed devices.
The approach adopted by the FCC is to require devices to use spectrum sensing to avoid interfering with nearby wireless microphones, although as a precautionary measure some channels have been reserved for wireless microphones in major markets.
Initially, manufacturers will be required to incorporate a geolocation facility that is used in conjunction with Internet access to a database of incumbent services. This will allow such devices to avoid interfering with nearby wireless microphones, TV stations, cable TV head-ends and other spectrum users.
In the future, the FCC may approve devices that solely rely on spectrum sensing following an especially rigourous testing process.
"Our testing has shown that this approach [spectrum sensing alone], right now, is not ready for prime time," said commissioner Michael Copps.
What will be involved in getting a device approved? See page 2.
The approval process will include laboratory and real world testing, and the FCC will remove from the market any devices subsequently found to cause harmful interference. The geolocation system will provide a way of automatically disabling specific models found to be faulty, presumably be making the whole country a 'no go' zone for them.
The spectrum being released allows transmitters to cover a wide area and provide high data rates. Furthermore, the signals readily penetrate buildings, giving the tin foil hat brigade yet another wireless signal to be worried about, while keeping the rest of the wireless broadband hungry population happy.
Microsoft's chief research and strategy officer Craig Mundie welcomed the decision, saying "it will allow every American to realise the enormous potential of white spaces" and that it "ushers in a new era of wireless broadband innovation".
Larry Page, co-founder of archrival Google described the FCC's decision as "a clear victory for Internet users and anyone who wants good wireless communications."
"I've always thought that there are a lot of really incredible things that engineers and entrepreneurs can do with this spectrum. We will soon have 'Wi-Fi on steroids,' since these spectrum signals have much longer range than today's Wi-Fi technology and broadband access can be spread using fewer base stations resulting in better coverage at lower cost," he added.
Not all the commissioners were 100 percent behind the proposal - see page 3.
Hardware companies are also in favour of the change.
"Motorola looks forward to developing products to market that will help consumers realize the full potential of the TVWS including the opportunity to make broadband access, as well as other communication services, available to millions of underserved Americans," he added.
While all five commissioners voted in favour of the move, commissioner Deborah Taylor Tate issued a statement dissenting in part with the decision.
She expressed regret that the order does not specifically state the legal responsibilities of those who provide the devices: "I wanted to ensure that our rules specify that, in the event of significant interference caused by an unlicensed device, the party responsible for this device will also be responsible for rectifying the problem and assume the cost. [Her emphasis]
Tate also wanted to see specific steps to address higher-power fixed operations in rural areas as a possible mechanism to provide broadband backhaul, and she favoured the reservation of a proportion of the white spaces for licensed use. Licensing could bring in from $US8 billion to over $US24 billion, she suggested.
On the other hand, Copps noted in his statement that "the airwaves, after all, are the people's airwaves." [His emphasis]
Now we need to get beyond the talk to the development and deployment of devices. That could take some time, but what was once white will soon be filled with the endless colour of wireless data.