Radio broadcasts, television signals and mobile communications have filled up the airwaves rapidly in recent years, prompting the need to overcome crowded bandwidths that hamper the growth of technology. Cognitive radio technology, which automatically detects and exploits available channels in the wireless spectrum, could help address this high-tech challenge. The technology relies on efficient spectrum sensing (SS) and primary user (PU) detection of cognitive radio networks (CRNs), representing two key challenges in this respect. Against this backdrop, the EU-funded project 'Cooperative spectrum sensing algorithms for cognitive radio networks' (COSSAR) aims to overcome obstacles related to SS and PU detection. Researchers will investigate options to assist CRNs in detecting spectrum holes and exploiting underused frequency bands without interfering with PUs. More sophisticated methods will be required to capture the necessary information from the airways in order to streamline CRN operation. To achieve its aims, the project team is developing advanced detection algorithms that can operate in various environments. They are working on improving the signals- estimation method using the concept of adaptive set-theoretic filters. Experiments conducted have already shown that the proposed solution was able to improve detection of desired spectrum holes and enhance cognitive radio technology. Through this endeavour, the concept of cognitive radio could be the answer to maximising the utilisation of limited bandwidth. This will facilitate a rise in additional services and applications in wireless networks, encouraging technological growth and competitiveness. Communication and openness will prevail.