On December 22, 2011, the FCC announced approval of the first television white spaces database and device. This announcement will have an impact on you in the future. An additional relevant FCC announcement can be found here.
In layman’s terms, white spaces are the parts of the radio spectrum that exist between broadcast television stations and any unused channels in any particular television market. As part of the switch to digital television which occurred in 2009, additional parts of the spectrum became available. Under normal circumstances, these parts of the spectrum are sold and licensed for specific television channel use. This new plan allows for the unused space to be considered unlicensed and available for use by others. Many broadcasters are quite concerned over the possibility of these white space devices interfering with their broadcast spectrum. Common expected uses of this technology include offering broadband to communities (like rural areas, small towns or college campuses), transmission of signals to and from traffic cameras, monitoring of public and private areas (rest stops, public parks, and livestock), medical telemetry and other public safety uses.
The real value of these parts of the spectrum is that, due to their frequency and wavelength, they have the ability to penetrate buildings and other structures with ease. These structural limitations hamper the use of other technology, like cordless phones, baby monitors and Wi-Fi devices that normally operate in the 2.4 GHz area of the spectrum. In addition, these signals can carry over significantly longer distances with improved payload.
There are a few technical hurdles with the use of this white spaces technology. The first has to deal with how you can tell which frequencies are available in any particular geographic area for unlicensed use. The second is the development of radio equipment that can take advantage of the available frequencies. Solutions currently exist for both of these issues.
The solution to the first issue is to track the use of licensed spectrum in specific areas by location. The plan is to have a handful of companies administer databases containing the spectrum use information. The first approved company in this category is Spectrum Bridge, Inc. Approval of about ten database administrators is likely, including Google and Microsoft.
The solution to the second issue is the development of software-defined radios which can adjust transmit power, gain and frequency to comply with the goal of avoiding interference on previously allocated channels or when competing signals are detected. Koos Technical Services, Inc., makes the first officially approved device that complies with the FCC ruling. Details of the product can be found here. This first devices will work in conjunction with the Spectrum Bridge database and is expected to go online for a live trial Wilmington, NC, on January 26, 2012. This trial will involve bringing broadband internet service to this rural area. Upon successful trials here, the technology will likely be expanded to other areas of the country.
Much debate (and here and many others) has occurred about how best to handle the use of this spectrum. Some claim it is akin to real estate and it should be auctioned off to the highest bidder for exclusive use. In my opinion, the prevailing decision favors the true advancement of technology over continued corporate greed. Several articles I have read seem to point to the significant advances that happened in technology due to the free and open availability of the Wi-Fi bands more than a decade ago. Although many billions of dollars could have been made through the sale of this spectrum, the impact to the economy could be far greater if all can use this spectrum freely. The FCC’s decision clearly supports this notion. Many companies, such as this one, are already positioning themselves for the inevitable push to market this new technology.
Although not a doctor, (I don’t even play one one TV), I do have some concerns over the potential health risks associated with the use of the white spaces technology. The thing that makes the proposed use of this spectrum suspect for me is that it is two-way. That is, in order to use this spectrum as intended, you must not only be passively receiving the signals (like a TV), but that you are transmitting with some higher level of power to also send data over these frequencies back to another receiver. Studies have shown that it is not only the frequencies being transmitted, but the general proximity of a high-powered transmitter that can cause harm. Granted, the power of these transmitters will likely be significantly less than those used for a normal television broadcast, but they will need to be higher than a standard Wi-Fi, Bluetooth device or cell phone as well. An article that discusses more of the potential health risks can be found here. My goal is not to be an alarmist, just a cautious adopter of this technology.
I do believe that this technology will be adopted and widely used. I also believe a bit more study and governance may be required to protect the safety of the general public from misuse or abuse of this new slice of the technological pie.