Energy-Harvesting Cognitive Radios in Smart Cities

Wireless communication has been experiencing tremendous advancements. These 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 efficient and smarter way. The smart city is a vision that extracts information from systems in the city to take measures for its management. This vision can be realized if information 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). The transmission of the sensor observations about the city needs Internet connection to inform city officials. This fact leads to the utilization of the IoT 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). This 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. The smart city uses information and communication technologies to manage cities in an integrated manner (Zhang, 2010). The 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