The company has wasted little time preparing to fill the vacuum. Last year, Microsoft Research set up a wi-fi–like network on its Redmond, Wash., campus to transmit high-speed data signals over white spaces using a technology the company refers to as "WhiteFi." Engineers from Microsoft's Networking Research Group received permission from the FCC last year to test a live WhiteFi network stretching over a 2.6-square-kilometer area of the campus to determine whether wireless devices would be able to get a high-speed connection without interfering with the TV broadcasts and wireless mics used in nearby buildings. "We needed to see what such a network would look like in the wild," says Ranveer Chandra, a researcher with the group.
One scenario enabled by Microsoft's WhiteFi network is the ability to give wireless users Internet access while they ride the 220 shuttle buses and cars used to transport employees and visitors around the company's city-size campus. The researchers installed a wi-fi access point in one such shuttle. The access points get their wireless signals from WhiteFi antennas set up last October and then hand off the connection to mobile devices on the shuttle via wi-fi. They rely on a prototype database Microsoft created to find vacant portions of the broadcast spectrum.
Channel sharing
Microsoft Research continues to test its WhiteFi network. A particular area of interest moving forward is the WhiteFi's ability to divide spectrum channels so that a tablet PC, for example, could share that space with a wireless mic. Right now, this is a no-no—the FCC prohibits a white space device from sharing channels with wireless mics, even if that mic does not use the entire channel. The researchers are experimenting with ways to snag the unused portion of the channel for data transmission without interfering with that of the mic, Chandra says.
To ensure there is no interference, Chandra and his team are testing white space transmissions in an anechoic chamber, whose walls absorb sound to prevent echos and reverberations. In the chamber they record sounds via a wireless mic, at the same time exposing it to white space transmissions (they also make recordings without any white space transmissions). Then they analyze the quality of the recording using a set of standards known as perceptual evaluation of speech quality (PESQ), also used by phone-makers, network equipment vendors and telecom operators to assess voice quality. Their results show that vacating only a few 100 kilohertz of a six-meghertz TV channel is sufficient to avoid audible interference to wireless mics. The remaining spectrum can be simultaneously utilized for high-speed data communication.
Mobile phones, PCs and access points enabled for both wi-fi and white spaces could hit in the market in roughly two years, Reed says.
White space connectivity is needed, particularly as information technology reaches new heights—demand for wireless content will grow anywhere from five to 40 times what it is today within the next decade and a half, Reed says. The next big frontier is likely to be wireless video, which would let mobile phone users stream live video (a baseball game, for example) to their handsets with low latency. Wi-fi and cell networks are not prepared for this type of traffic, he says, adding, "Think about the challenges that carriers are facing now just to support smart phones."
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8 Comments
Add CommentThe FCC should have done some more homework before allowing this to happen. Magnetism is normal to everything living on the planet, electromagnetism and these frequencies are very very dangerous.
Reply | Report Abuse | Link to thisSome pretty basic electrical theory shows what happens when you have very fast frequencies interacting with biologic systems running at 7.8 Hz. The lower frequencies are uninsulated, unprotected electrical signals and interaction with these high frequencies is causing electrical problems. In human tissue induced currents have shown to cause nerve and muscle depolarization. Ask a doctor what happens if nerves don't work?
Bees, pollinators and ecosystems are different frequencies that will be dramatically impacted by these frequencies and they are responsible for our food sources. Wireless is convenient but not safe, as electrical professionals we pull cables with proper protection for the signal as well as the human.
Mr Obama has stated that health costs can bankrupt the US Government, get ready because the health costs will be substantial. Even the wireless industry doesn't want to be responsible for these health costs as the offset would have them bankrupt. Here is a link to a press release on the electrical conflicts. http://www.thermoguy.com/blog/index.php?itemid=45
It is illegal to sell out children and ecosystems for profit. We need to smarten up and do the homework first or we will pay the price.
Aside from the frequencies opened up, with essentially unrestricted unlicensed TV stations potentially operating on every block at the amplitudes of prior regional TV stations, there could be some at least hypothetical potential for dangerous exposures to EM radiation...
Reply | Report Abuse | Link to thisIf some deviant wished to produce a real ray gun, this might be an opportunity.
Otherwise, this could be a great Christmas gift: a new HiFi Mr. Microphone! You know - for the kids.
I don't get it...the frequency they're talking about is way lower than the existing 2+gigahertz for wi-fi(a,b,g,n)...
Reply | Report Abuse | Link to thisvhf is 30mhz-300mhz...the best though put should be less than 1 tenth the current spectrum...
probably better range but that's it...
Maybe I'm missing something....
As I understand, these are the frequencies that had been used for TV stations for so long before the digital TV conversion last year. It states: "TV white space spectrum is considered prime real estate because its signals travel well, making it ideally suited for mobile wireless devices."
Reply | Report Abuse | Link to thisThis is made clearer in the referenced link to the FCC order document "FCC FREES UP VACANT TV AIRWAVES FOR “SUPER WI-FI” TECHNOLOGIES", which states that the order "requires (low power) wireless microphone users who seek to register in the TV bands databases to certify that they will use all available channels from 7 through 51 prior to requesting registration."
Isn't vacating EM communications the ultimate goal of new technology. Photonic based technology is replacing EM communications, I consider vacating bandwidth ranges like reclaiming industrial space for parks and trees.
Reply | Report Abuse | Link to thisAs specified in the FCC documents referred to, these EM frequencies are being made generally available with the thought that the can be useful in facilitating mobile communications, particularly mobile Wi-Fi. Providing mobile communications with either optical fiber or directed beam optical (EM) laser transmissions would prove technically challenging.
Reply | Report Abuse | Link to thisIMO, 'photonic' transmissions require the emission of EM light waves to propagate through space, even when guided by optical glass fibers: the EM waves are manifested as photonic particles only when they are detected by materially absorbing their momentum.
Photonics cannot replace all EM communications. This much is obvious. Taking down EM background instead of filling up the vacated slots with unnecessary applications is what I was referring to.
Reply | Report Abuse | Link to thisThe effects of EM background noise on life has always been a research taboo. The few researchers who risked their academic careers doing such research have raised enough alarm to consider downsizing our use of EM bands as a positive step.
The effect of background EM harmonics on life is still unpredictable and has yet to be assessed without censorship and researcher intimidation.
No one would admit new drugs to enter the market without prior testing...
Sorry I misunderstood your earlier comment, and thanks for explaining so well. I generally agree with your concern, especially considering that the unregulated use of this established bandwidth risks a potential explosion of high powered transmitters using off-the shelf component production. While unlikely, it seems possible that we could soon find the energy emission equivalent of a TV station transmitter on every block, delivery van or parking lot bus...
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