Microsoft researchers may have taken a step closer to finally turning unused analog TV spectrum, known as "white spaces," into unlicensed spectrum that can be used to deliver new wireless broadband services.
Researchers from the software giant, along with academics from Harvard University, have developed a protocol that the company claims could be the foundation for products that meet Federal Communications Commission requirements for avoiding interference when using unlicensed "white space" spectrum. The researchers presented their ideas this week at the ACM SIGCOMM 2009, a communications conference held in Barcelona, Spain, according to an article published on MIT's Technology Review Web site.
"White space" spectrum is unused wireless spectrum that sits between analog TV channels. Because much of this spectrum operates at lower frequencies, it can travel longer distances, much longer distances than the unlicensed frequencies used for Wi-Fi devices. Most Wi-Fi devices operate at 2.4 GHz, whereas, white space spectrum between analog TV channels 21 and 51 operate in the 512 megahertz and 698 megahertz range. (Signals transmitted over lower frequencies tend to travel longer distances at slower speeds, while signals transmitted at higher frequencies tend to be faster over shorter distances.)
Technology companies, such as Google, Motorola, Microsoft, and Dell, have been lobbying the FCC for years to open this spectrum for unlicensed use. The hope is that the spectrum could be used to augment existing wireless services or eventually be used to create new wireless broadband services.
But TV broadcasters and wireless microphone companies have long opposed the use of this spectrum, saying it will interfere with their services.
After a series of prototype tests, the FCC in November finally agreed to open up unused broadcast TV spectrum for unlicensed use. But the commission put together a set of strict guidelines designed to ensure that devices using the unlicensed spectrum would not interfere with existing TV broadcasters or other devices using the same unlicensed spectrum, such as wireless microphones.… Read more