Fog Computing Complete Review: Concepts, Trends, Architectures, Technologies, Simulators, Security Issues, Applications, and Open Research Fields

Regarding real-time data processing, technological innovations like the Internet of Things (IoTs) need latency-sensitive computation. The interconnected devices in IoT systems produce enormous amounts of data. In most cases, a cloud platform is used to compute these data. But for some IoT services, particularly time-sensitive ones, computation requests only on the cloud is not an effective option. For services that depend on low latency, the distance among the cloud servers and the IoT/ edge devices may be a problem. Fog computing (FC), which sits between the cloud server and edge devices, was suggested as a solution to this problem. Edge devices are typically attached to fog devices (i.e., fog nodes) in the FC platform. Edge users can find these fog nodes nearby, and they are in charge of intermediary computation as well as storage. Since FC platforms are still in their development and are steadily rising, rigorous investigation is essential for understanding this novel technology. The industry as well as academic society will be able to learn more about the specifications for constructing an FC platform with a clearer understanding of all components of the fog, thanks to this complete review work. This paper begins with an introduction to FC concepts, where the reason of fog emergence, its definition, characteristics, implementation practices, and a comparative study among fog, cloud, and edge computing are discussed. Next, records from Google Scholar as well as three top academic databases (i.e., ScienceDirect, IEEE Xplore, and ACM digital library) are gathered and analysed to determine the research trend on FC. Then we categorize the various recommended FC architectures into three categories and the aspects of these architectures are then thoroughly described. We then go into great detail on the technologies used to create fog systems. Here, six key technologies, their features, a thorough description of each, and related research efforts are thoroughly presented. In addition, 43 fog simulators are described in this study while taking into account 5 factors and analysed them by considering four parameters. The following two chapters go into great detail regarding the security concerns and applications of fog. Ultimately, by discussing the shortcomings of recent research studies, we highlight several unresolved problems that will define the future course of the fog platform's study.