ECC Report 159: European white space devices
The document studies three candidate techniques to be implemented by the cognitive radio devices, namely sensing, geo-location database and beacon. However in a similar line to the FCC conclusion the report indicates that the current technology is not adequate for sensing based standalone systems:
"The sensing thresholds were derived for a limited number of scenarios using the methodology developed within this report and taking into account a range of potential DTT receiver configuration. Some of the values so obtained (being in the range from -91 to -165 dBm depending on the DTT planning scenario) appear to be too low to be implemented using the current technology. Moreover, in some scenarios, even these low values for the detection threshold do no guarantee a reliable detection of the presence/absence of the broadcasting signals at the distance corresponding to the interference potential of a WSD."
While the ECC Report 159 also studies the combination of sensing and geolocation database to assure the required protection to primary users, the ECC will probably conclude that geolocation based devices offer enough protection without additional sensing. This may look as bad news for the companies which invested in spectral sensing research. However, as Roberto points out in a comment of the last post spectrum sensing devices may be useful to build and keep up to date the information present in the database.