3 1 Energy-Harvesting Cognitive Radios in Smart Cities Mustafa Ozger 1 , Oktay Cetinkaya 1 and Ozgur B. Akan 2 1 Research & Teaching Assistant, Next-generation and Wireless Communications Laboratory, Koc University, Turkey 2 Professor of Electrical and Electronics Engineering, Director of Next-generation and Wireless Communications Laboratory, Koc University, Turkey 1.1 Introduction Wireless communication has been experiencing tremendous advancements. Tese developments have triggered new wireless networking paradigms and communication services. For instance, 5G is being studied by the research community to provide mobile broadband communications in wireless networks. Recently, the concept of IoT (Atzori et al., 2010), which is one of the key elements of 5G wireless networks, has been proposed to connect every device to the Internet, such as wireless sensor nodes, RFID tags, household appliances, etc. As these technologies grow, they have been applied to various real-world problems. One of the most important application areas is the management of cities in a more effi- cient and smarter way. Te smart city is a vision that extracts information from systems in the city to take measures for its management. Tis vision can be realized if informa- tion and communication technologies are employed in these systems to observe and manage them. Wireless sensors can be utilized as key elements for observing systems such as hospitals, highways, transportation networks, and power grids (Su et al., 2011). Te transmission of the sensor observations about the city needs Internet connection to inform city officials. Tis fact leads to the utilization of the Io T since it can integrate all the facilities of the city with the Internet. Hence, the realization of the smart city vision becomes possible since the systems can be sensed, analyzed, and integrated with the use of communication technologies (Jalali et al., 2015). Tis enables the ability of managing the city in a cleverer and more efficient way in terms of city infrastructure, services, communication, business, energy, water, and so forth. Te smart city uses information and communication technologies to manage cities in an integrated manner (Zhang, 2010). Te holistic view of the smart city can be seen in Figure 1.1.1, where smart grid, smart Transportation, smart communication, smart building, smart home, and smart infrastructure are bound together. With the use of next-generation information technologies, core systems are sensed, and the extracted information is analyzed for better management of the city and for improving quality of life in cities. To this end, it is envisioned that sensors are being deployed in different Transportation and Power Grid in Smart Cities: Communication Networks and Services, First Edition. Edited by Hussein T. Mouftah, Melike Erol-Kantarci and Mubashir Husain Rehmani. © 2019 John Wiley & Sons Ltd. Published 2019 by John Wiley & Sons Ltd. COPYRIGHTED MATERIAL