Abstract: Need of wireless sensor network (WSN) is increasing in various application areas. Resource restricted Traditional WSN is not able to satisfy this increase in demands. Many WSN is using unlicensed band (ISM band) so this band become overcrowded. Cognitive radio in WSN with opportunistic behavior and dynamic spectrum access can satisfy increasing demands and utilized spectrum bands effectively and efficiently. In this paper detail study of Cognitive Radio Sensor Network (CRSN) with architecture, hardware structure and challenges are explored.

Keywords: cognitive radio, dynamic spectrum access, spectrum sensing.