WHITE SPACES
White spaces is used to denote the unused frequencies between assigned frequency bands. White spaces are necessary to prevent unwanted interference between adjacent frequencies. When the FCC decided in 2006 that the Television network should go all-digital in 2009 the a consortium of technology companies formed the White Spaces Coalition. This group has successfully lobbied to make the frequencies permanently white spaces and available for unregistered devices.

WIFI, WIMAX
WiFi (IEEE 802.11) is the extremely popular wireless local area network operating in an unlicensed frequency spectrum. Its intended use is for static devices, or perhaps a laptop. But mobile devices equiped with WiFi also enjoy the base stations that are intentionally left open. WiMAX (IEEE 802.16) is something else entirely. WiMAX operates in a licensed frequency spectrum and because of that limited to operators that acquired to right to operate. The specification was originally designed for broadband access (comparable to White Spaces we are talking about here) but has soon been augmented for mobile broadband access.

WHITE SPACES
IEEE 802.22 is best compared to static WiMAX but unlicensed. As a technology it is intended to be used to provide broadband access to the home. Operating on one television channel the approximate maximum bit rate is 19Mbit/s at a distance of 30 km. White Spaces as specified now is not a competitor to 3G/4G but to WiMAX/ADSL/Cable last mile offerings.

EXPECTATIONS
I find it difficult to understand why the FCC would auction the WiMAX frequency in Januari and give away the White Spaces frequencies in November of the same year. WiMAX operates in higher frequencies, potentially capable of much higher transfer rates than possible with the White Spaces frequencies. But we are squeezing a lot of out of cable and ADSL copper cables as well, much more than initially expected.

For the USA Google expects to reach the rural areas with broadband. The broadband penetration is not that high in the USA, only 50% in 2008. With White Spaces a success Google would automatically gain a lot of traffic. In Europe it is more difficult to find a direct application of this technology. I am inclined to expect more from the semi-wireless application with mobile devices, in the same way the iPhone is now using WiFi hotspots.