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In this chapter, MFC has its specific definition and it is not an exchangeable terminology with the other similar terms, such as mobile cloud computing (MCC) or multi-access (mobile) edge computing (MEC). In order to clarify the meaning of MFC, one needs to understand the aspects of the parties who introduced or adapted the terminologies. Commonly, MCC refers to a system that assists mobile devices (e.g. smartphones) to offload their resource-intensive computational tasks to either distant cloud [7] or to the proximity-based cloudlet [8].

Fundamentally, MEC is an European Telecommunications Standards Institute (ETSI) standard aimed to introduce an open standard for telecommunication service providers to integrate and to provide infrastructure as a service (IaaS), platform as a service (PaaS), or software as a service (SaaS) cloud services from the industrial integrated routers or switches of their cellular base stations. Explicitly, MEC is an implementation approach rather than a software architecture model. Further, as stated by ETSI, ETSI and OpenFog are collaborating to enable the MEC standard and the OpenFog Reference Architecture standard (IEEE 1934) to complement each other [9].

Today, researchers of industry and academia have been broadly using edge computing as the exchangeable term with fog computing. However, National Institute of Standards and Technology (NIST) and the document of IEEE 1934 standard for fog computing reference architecture, which derives from OpenFog Consortium, have specifically explained the differences between fog computing and edge computing. Accordingly, “the Edge computing is the network layer encompassing the end-devices and their users, to provide, for example, local computing capability on a sensor, metering or some other devices that are network-accessible” [10]. Further, based on the literature in edge computing domain, which include cloudlet-based computing models [11], one can explicitly identify that edge computing is loosely a bottom-up model. Specifically, an edge computing-integrated system emphasizes task offloading from the end-devices to the nearby cloudlet resources, which are capable of providing Virtual Machine (VM) or containers engine (e.g. Docker¹)-based service to the other nodes within the same subnet.

On the other hand, fog computing is a hierarchical top-down model in which the system specifically tackles the problem about how to utilize the intermediate networking nodes between the central cloud and the end-devices to improve the overall performance and efficiency. Commonly, such intermediate nodes are Internet gateways such as routers, switches, hubs (e.g. an adaptor that interconnects Bluetooth-based device to IP network). Moreover, a fog node is capable of providing five basic services – storage, compute, acceleration, networking, and control [1]. Correspondingly, when a cloudlet or an IoT device is providing gateway mechanism to the other nodes and they are capable of providing some or all of the basic fog services, we also consider them as fog nodes.

By extending the notion above, MFC is the subset of fog computing that addresses mobility-awareness. Specifically, MFC involves two types – infrastructural fog (iFog)-assisted mobile application and mobile fog node (mFog)-assisted application. In summary, iFog-assisted mobile application enhances the performance of a cloud-centric mobile application by migrating the processes from the central cloud to the stationary fog nodes (e.g. the cellular base station) that are currently connecting with the mobile IoT devices. On the other hand, mFog-assisted applications host fog services on mobile gateways (e.g. in-vehicle gateway devices or smartphones) that interconnect other devices (e.g. onboard sensors, body sensors, etc.) or other things (e.g. proximal cars, people, sensors, etc.) to the cloud.