"Many spectrum measurements have evidenced great temporal and geographical variability in the usage of licensed spectral bands. In conjunction with fixed spectrum assignment policies and the limited amount of available radio spectrum, this results in low efficiency in the use of this scarce resource. Cognitive radios provided with Dynamic Spectrum Access (DSA) capabilities will improve this situation by granting unlicensed 'secondary' networks access to licensed bands in an opportunistic manner, as long as interference with licensed 'primary' networks is kept at tolerable levels. The capability to detect spectrum holes, without interfering with the primary network currently in use, is one the actual major difficulty faced by the cognitive radio, all the more as a fine granularity of allocation (time and frequency) is targeted. WISERNETS project will focus on developing innovative techniques based on wireless sensor networks to perform the sensing of the cognitive radios, supporting the coexistence of licensed primary and unlicensed secondary wireless users in a same area, analyzing also fundamental limits of performance using sofware defined radio terminals. This technology will allow addressing a very dynamic and competitive mixed radio access between cellular and broadband technologies. The sensor network aided cognitive radio proposed and studied in this project will address several objectives, including: a) novel spectrum distributed sensing techniques to be able to identify spectrum holes, b) corresponding information management and exploitation to achieve the co-existence of cognitive secondary radios with primary licensed technology, without generating harmful interferences. The project will integrate a wireless sensor network for cognitive radio with sofware defined radio terminals to emulate primary and secondary users. This demonstrator will be used to evaluate the performance of the proposed architecture."