Fog computing for sustainable smart cities in the IoT era: Caching techniques and enabling technologies - an overview

In recent decade, the number of devices involved with the Internet of Things (IoT) phenomena has increased dramatically. Parallel to this, fog computing paradigm has been introduced in order to support the computational demand of latency-sensitive and real-time IoT applications. The main support the fog paradigm can provide for these applications is through enabling computing at the edge of the network closer to the end users and IoT devices. Moreover, in sustainable smart cities, fog computing can be utilized as an efficient framework to reduce delays and enhance energy efficiency of the system. This article considers possible fog computing applications and potential enabling technologies towards sustainable smart cities in the IoT environments. In addition, different caching techniques and the use of Unmanned Aerial Vehicles (UAVs), and various Artificial Intelligence (AI) and Machine Learning (ML) techniques in caching data for fog-based IoT systems are comprehensively discussed. Finally, the potential and challenges of such systems are also highlighted.