Following current trends towards dynamic spectrum allocation and cognitive radio, this paper proposes a new approach and innovative techniques to support the coexistence of licensed and unlicensed wireless users in a same area. The proposed concept, called Sensor Network aided Cognitive Radio, consists of a wireless sensor network able to assist the cognitive network by providing information on the current spectrum ccupancy. This concept, that will address various operational scenarios in the future networks, involves a set of advanced wireless communications techniques like spectrum sensing, interference management, cognitive radio reconfiguration management, cooperative communications, end-to-end protocol design and cross-layer optimisation. All these enabling techniques together will form a compound system able to improve the spectrum use in a significant way. The main target scenario we consider is the use of nomadic cognitive radios in urban and suburban areas. Our objective is to develop a proof-of-concept -scheduled in 2010 - of the Sensor Network aided Cognitive Radio technology by implementing such techniques and integrating them on a hardware radio platform, which will allow us to assess the efficiency of the technology in a realistic environment.
