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Top1. Introduction
Fog computing, also known as ‘fogging’ or ‘fog networking’, is a decentralized computing framework through which the computers, data storage, and applications are dispersed in the most efficient and logical place among cloud and data sources. The main goal of fog computing is the enhancement of efficiency & decrement of data transportation to cloud for the development, examination, and storage as shown in Figure 1, by the general architecture of fog computing (Roman, Lopez, & Mambo, 2018). In fog, the development takes place in smart devices or data hub on the smart devices, gateways or smart routers. Therefore, it is better to lessen the data amount transferred to the cloud. There is an issue of interoperability for varied hardware nodes in fog computing, so, there is a requirement of a feasible solution for developing unified software and virtual objects on the nodes for representing heterogeneous physical entities.
Figure 1.
Fog computing general architecture
Cloud computing is a promising solution for on-request access to a mutual pool of virtualized arranged assets based on desired Quality of Services (QoS) and pay-as-you-use pricing model. It provides high computational and storage capabilities for IoT (Botta, De Donato, Persico, & Pescapé, 2016). Even though cloud computing can provide so many facilities like storing a large amount of data, but there are challenges for IoT applications such as lack of limited network bandwidth, mobility support, latency, and location awareness. So as to overcome the above issues “Fog computing “turned as a promising foundation to cloud solution as it works on the edge of the system”” (Li, Xiaoguang, Ke, & Ketai, 2011). It provides communication between IoT devices and cloud computing on a large scale to deliver better facilities without the constraints mentioned in Table1 (Hu, Dhelim, Ning, & Qiu, 2017). Table 1 illustrates the requirements of IoT from cloud computing to the fog computing.
Table 1.
Fog-cloud key requirements
| Key Requirements | Cloud Computing | Fog Computing |
| Delay jitter | High | Very low |
| No. of server nodes | Few | Very large |
| Location of service | Within the Internet | All the edge of the local network |
| Location awareness | No | Yes |
| Mobility support | Limited | Supported |
| Real time interactions | Supported | Supported |
| Distance between client and server | Multiple hops | One hop |
| Type of last mile connectivity | Leased line | Wireless |