Podcast Audio | Posted by Phil Leigh on May 3, 2011
Last week (April 29th) Microsoft notified the FCC it wants to be an administrator for TV Band White Spaces.
Interpreting the announcement’s significance requires an accurate comprehension of much misunderstood TV Band White Spaces. Put briefly, the FCC has reserved enough spectrum for about fifty TV channels. Since each station has a limited broadcast contour, channels can be reused in different parts of the country. To illustrate, different station owners use channel 7 in New York, Detroit, Chicago, Denver, Albuquerque, San Francisco, and San Diego without interfering with one another, owing to geographic separation. Theoretically, each city has fifty channels available, but FCC regulations require that stations not interfere with those in nearby cities. That’s why WABC can broadcast on channel 7 in New York City, but no station may use channel 7 in close-by Newark, New Jersey.
Nonetheless, there are many localities where a number of the fifty reserved TV channels are simply unused. Last September the FCC ruled that such channels can be employed by non-TV devices. Foremost among them will be smartphones, Wireless LAN routers, and Wireless ISP transceivers. A key requirement is that such devices avoid interference with operating TV stations. Non-interference is accomplished by equipping such units with electronic circuits that leverage on-board geo-location capabilities to query an online database of TV station broadcast profiles. The procedure enables White Space devices to promptly identify vacant TV channels and use them for Wireless networking, including Wireless Internet.
Two points merit emphasis.
First, construction of White Space networks, such as Wireless LANs, does not require an FCC license. That’s because interference avoidance is implemented in the automatic manner previously described. Consequently, equipment and software providers such as Microsoft can rapidly develop market potential, much as they did Wi-Fi. In or analysis, Microsoft’s application for administrator status implies it intends to offer integrated solutions capable of minimizing friction in the automated channel identification process.
Second, TV bands can be put to good use for Wireless LANs and ISPs which have discovered limitations with the frequencies available for Wi-Fi. Specifically, TV bands propagate further and can better penetrate walls and enter buildings. Thus, if provided with White Space capability, the wireless routers in our homes could reliably send signals to distant rooms where Wi-Fi reception has proven to be unsatisfactory. Such a router could enable us to stream Internet video all over the house.
In conclusion, Microsoft already operated an experimental TV Band campus network in Redmond, Washington. Now that White Spaces are authorized for commercial use, it appears Microsoft is ready to help the industry reach its potential. Since Google – among others – has already been granted administrator status, Microsoft’s addition underscores the importance which major industry factors are attributing to TV Band White Spaces.
To learn more, readers are invited to consider our research report, “TV Band White Spaces: Analysis and Forecast” which is available from The Diffusion Group.