Interest in smart cities is rapidly rising due to the global rise in urbanization and the wide-scale instrumentation of modern cities. Due to the considerable infrastructural cost of setting up smart cities and smart communities, researchers are exploring the use of existing vehicles on the roads as "message ferries" for the transport data for smart community applications to avoid the cost of installing new communication infrastructure. In this paper, we propose an opportunistic data ferry selection algorithm that strives to select vehicles that can minimize the overall delay for data delivery from a source to a given destination. Our proposed opportunistic algorithm utilizes an ensemble of online hiring algorithms, which are run together in passive mode, to select the online hiring algorithm that has performed the best in recent history. The proposed ensemble based algorithm is evaluated empirically using real-world traces from taxies plying routes in Shanghai, China, and its performance is compared against a baseline of four state-of-the-art online hiring algorithms. A number of experiments are conducted and our results indicate that the proposed algorithm can reduce the overall delay compared to the baseline by an impressive 13 to 258 .
Smart cities are a hot topic nowadays for several reasons. For city managers and citizens a smart city is a concept that should allow providing better services and or with more efficiency. For technicians a smart city represents one of the large-scale deployments of equipment for data capturing, storage and processing. For Internet researchers a smart city can become the first massive installments of the Internet of Things concept. Smart cities are commonly implemented in several parts: the data acquisition and actuation, the aggregation networks that connect sensors actuators with the general purpose network, the platform where data is stored and processed and the application that use the information for informing the city managers and citizens. The most costly parts of a smart city are the sensor actuator and the aggregation network. This cost is due mainly due to the deployment and maintenance of the equipment on the city street. This paper describes the different alternatives for building the aggregation networks and provides a novel approach to facilitate the deployment of a smart city. This new solution has been tested in a real scenario achieving satisfactory results. © 2014 IEEE. Significant advancements in various technologies such as Cyber-Physical systems (CPS), Internet of Things (IoT), Wireless Sensor Networks (WSNs), Cloud Computing, and Unmanned Aerial Vehicles (UAVs) have taken place lately. These important advancements have led to their adoption in the smart city model, which is used by many organizations for large cities around the world to significantly enhance and improve the quality of life of the inhabitants, improve the utilization of city resources, and reduce operational costs. However, in order to reach these important objectives, efficient networking and communication protocols are needed in order to provide the necessary coordination and control of the various system components. In this paper, we identify the networking characteristics and requirements of smart city applications and identify the networking protocols that can be used to support the various data traffic flows that are needed between the different components in such applications. In addition, we provide an illustration of networking architectures of selected smart city systems, which include pipeline monitoring and control, smart grid, and smart water systems. Integrating the various embedded devices and systems in our environment enables an Internet of Things (IoT) for a smart city. The IoT will generate tremendous amount of data that can be leveraged for safety, efficiency, and infotainment applications and services for city residents. The management of this voluminous data through its lifecycle is fundamental to the realization of smart cities. Therefore, in contrast to existing surveys on smart cities we provide a data-centric perspective, describing the fundamental data management techniques employed to ensure consistency, interoperability, granularity, and reusability of the data generated by the underlying IoT for smart cities. Essentially, the data lifecycle in a smart city is dependent on tightly coupled data management with cross-cutting layers of data security and privacy, and supporting infrastructure. Therefore, we further identify techniques employed for data security and privacy, and discuss the networking and computing technologies that enable smart cities. We highlight the achievements in realizing various aspects of smart cities, present the lessons learned, and identify limitations and research challenges.