Microsoft has developed a Wi-Fi over Narrow Channels technology (Wi-FI NC), for television white spaces. It uses multiple radios on multiple narrow channels enabling available channels to be bundled together. It works like a regular Wi-Fi radio, only more efficiently, according to a story in Technology Review.
The team calls these transmitters and receivers “receiver-lets” and “transmitter-lets.” Together, they make up what’s known as a “compound radio“. Microsoft wants to enable license-free connectivity, like WiFi, using White Spaces, the unused television channels in the VHF and UHF band.
The Weightless specification (pdf), was developed as a machine-to-machine, low-cost, low-power communication system for use in the white space between TV channels in 2011 by engineers working at Neul in Cambridge, UK. Their specification is based on Time-division duplex technology with Spread spectrum frequency hopping.
“It is our opinion that WiFi-NC’s approach of using multiple narrow channels as opposed to the current model of using wider channels, in an all-or-nothing style, is the more prudent approach for the future of Wi-Fi and white spaces,” says Krishna Chintalapudi of Microsoft Research.
Microsoft’s proposal would apparently gang different channels together for faster speeds. Their white space radio proposal integrates with a previous Microsoft White Space project called SenseLess (pdf), which does not require an rf “sniffer”. It uses a geo-coded database, such as the one provided by Spectrum Bridge, to tell a device whether it’s safe to transmit. WiFi-NC then chooses the bands of spectrum that have the least interference.
The FCC approved a white space operations in Wilmington, N.C., which will begin on January 26, 2012, using a Spectrum Bridge database. Spectrum Bridge
recently released a web site, called Show My White Space, that shows the white spaces available at a given location. Microsoft supports a similar front end to SenseLess, but it differs in that it does not rely on sensing.
Microsoft hopes WiFi-NC will persuade Congress to approve wider use of white spaces.
Rep. Greg Walden (R-Ore.), sponsor of the House spectrum bill and chairman of the Energy and Commerce subpanel on Communications and Technology, would auction tv frequencies to wireless companies, but eliminate “free” spectrum, similar to WiFi, on the television bands.
The Wireless Innovation Alliance, which hopes to preserve “unlicensed” white spaces in the unused television frequencies, is concerned about spectrum legislation that will stop new entrants into the wireless market through “incentive auctions” of broadcast spectrum that would allow only “licensed” users paying big bucks for spectrum.
According to FCC Chairman Julius Genachowski (pdf), “Unleashing white spaces spectrum has the potential to exceed even the many billions of dollars in economic benefit from Wi-Fi, the last significant release of unlicensed spectrum, and drive private investment and job creation.”
Yochai Benkler, Professor of law at Harvard University, says “incentive auctions” threaten the future of wireless innovation by eliminating unlicensed spectrum. Tech companies generally favor license-free use of white space spectrum. Like Wi-Fi, cheap or inexpensive spectrum spurs innovation and device use, they argue.
Related Dailywireless articles include; FCC Authorizes White Space Service in Wilmington, White Space Legislation Goes Dark, White Space War, Bills to Kill Unlicensed White Space?, White Space Trial Completed, White Space Trialed, Huawei to Trial White Space TD-LTE, NTIA “Finds” 1.5 GHz of Federal Spectrum, UK Delays 4G Auction Ofcom: White Spaces by 2013, UK Gets Free Public WiFi, Europe’s Digital Divide Auction,