What if Wi-Fi radio beams traveled not just a few hundred feet but stretched for several miles— unimpeded by trees, terrain and walls so that they could penetrate all the nooks and crannies within buildings? That is the promise of “white-space” wireless.
“White-space” is geek speak for television channels left vacant in one city so as not to interfere with stations broadcasting on adjacent channels in nearby cities. America’s broadcasting authorities reserved 50 or so channels for TV stations. But because of worries about interference, no metropolitan area has ever come close to using all 50 channels at its disposal. In rural areas, vacant channels (ie, white-space) have frequently amounted to 70% or more of the total bandwidth available for broadcasting.
Because digital signals do not “bleed” into one another—and can therefore be packed closer together, television networks now require little more than half the frequency spectrum they sprawled across previously.
The attraction of white-space is that the frequencies used for television broadcasting (54MHz to 806MHz) were chosen in the first place for the distance they could travel and their ability to penetrate obstacles. They were also good at transmitting information quickly. Where Wi-Fi can shuttle data at 160-300 megabits per second, white-space can do so at 400-800 megabits per second.
“Microsoft has been using just two experimental white-space antennae, instead of thousands of Wi-Fi access points, to blanket its 500-acre (200-hectare) campus in Redmond, Washington. With white-space hotspots capable of covering such wide areas, supermarkets, shopping malls, even local municipalities could use it to offer free (advertising-supported) internet services to their customers and local residents, to search the web and make free telephone calls using Skype, Google+, or something similar on their smartphones and other devices.
Pipe-dreams? Far from it. Technical hurdles remain, but the first “enterprise-level” pieces of white-space equipment are about to go into service, with commercial trials of various applications expected throughout 2012. How soon before individuals can buy $100 white-space routers for the home? The consensus view is 2015 at the very latest.” (Nick Valéry: Difference Engine columnist, The Economist)
The interesting issues in all of this are what happens to the telecoms companies – and how safe is your dividend, and how will white space be regulated. Lobbyists should make out like bandits, which the Grey Peregrinator thinks is often true.