IoT-Fog architectures in smart city applications: A survey

Smart cities improve the quality of life of people by utilizing the benefits of Information and communication technology (ICT) and the Internet of things (IoT). The applications of the smart city often rely on the cloud for services. No doubt cloud provides an ample amount of resources as a service but still it has limitations in terms of unreliable latency, mobility, and location awareness due to their multi-hop distance from the IoT devices. Fog computing avoids these limitations by providing services nearer to the edges. In this work we investigate the already proposed IoT-Fog based application specific smart city architectures and review them based on scalability, heterogeneity, mobility, energy conservation, latency, and security. Additionally, we discuss the applications and highlight the challenges that fog computing faces. We also present a case study of a smart city scenario with multiple applications of IoT.