Introduction to Fog Computing

Fog Computing

Fog computing is an extension of cloud computing paradigm. To understand it in a simple way, just look at a scenario of having milk everyday from a milk-shop. Its human nature that, if best and cost-effective milk is available from a near by milk-shop, we prefer to have it from there instead of having it from big milk Dairy which is far away. But if we need milk in large quantity for an occasion, then we may buy it from Dairy. Fog Computing is based on similar concept of having computation locally whenever possible. But, do request to cloud server when more computation and/or storage power is required. This article gives insight into what and why of Fog computing, applications, benefits and its limitations.

What is Fog Computing?

Fog computing (also referred to as an edge computing) is an extension of the cloud computing paradigm from the core of network to the edge of the network. It provides computation, storage, and services between end devices and traditional cloud servers [1]. Servers and other intermediate nodes may be considered as core of network. Desktop machine, mobile, smart device, machine or any equipment connected in a network as end point device/machine are considered as edge devices.

The fog computing brings the cloud closer to the things that produce data and act on it. The devices like as set-top boxes, access points, routers, switches, base stations, video surveillance cameras, or any such end devices near to the end points of network are called fog nodes. These fog devices should have computing power, storage, and network connectivity. They can be installed anywhere with a network connection, may be in a vehicle, on top of a power pole, on a factory floor, or railway track side.

Fog Computing

Above figure shows simple architecture of Fog network. It shows that edge devices (Car, Mobile, Desktop, etc.) are connected to Fog nodes. Fog nodes are again connected to servers. Whenever possible, Fog node provides service to edge devices. But if it can’t provide service, the request will be served by cloud servers.

In simple word, “computing at network edge in Fog devices is referred to as Fog Computing”. Purpose of this computing is to provide limited but required computing, storage and connectivity services to user near to network edge. It is one of the supportive computing paradigm for Internet of Things (IoT). It will dramatically boost the development IoT Applications.

Why Fog Computing?

Cloud computing has been most promising computing paradigm for on demand services for computing, storage, and connectivity. Though it has great importance, but with the advent of technology and development of Internet of Things (wearable computing, smart home/city, and large-scale wireless sensor network, etc.), there are issues like lack of mobility support, unreliable latency, and location-awareness.

Hence, there is a need of computing paradigm that helps in resolving the issues by providing services locally with low latency, anywhere and everywhere. Fog computing resolves these issues by seamlessly integrating edge devices (fog devices) and cloud resources. Cloud resources are provided at the edge by coordinating with cloud and geographically distributed edge devices.

The Fog computing paradigm is best suited for Internet of Things and real time big data analytics. It supports densely distributed data collection points. It is very much beneficial for advertising, entertainment, personal computing and other such applications. Fogging is able to provide the benefits by placing information and services near to the user at the network edge. That is why researchers and companies are more inclined towards the development of applications and services of Fog Computing.

Applications of Fog Computing

These section briefly lists different applications of Fog Computing.

Health Care

Smart health gadgets and devices can receive best services from fog devices at network edge. No need to send service request to cloud server.

Connected car

Fog device enables cars to talk with each other to avoid accidents. It also helps in getting information about low crowded path.

Smart Grids

Smart electric devices can switch to other energy sources like solar and winds based on demand for energy, its attainability and low cost.

Smart Traffic Lights

Fog enables automatic opening of signals based on dynamic situation of traffic signals. Also, it can detect ambulance and open lanes for it.

Smart Building Control

All sensors in the building can communicate and exchange with each other and with Fog device. Fog device performs analysis on combined data. Connected devices may react in response to data analysis and distributed decision making.

Self Maintaining Train

Fog devices can automatically detect disorder and alert the train operator to make required maintenance. Thus, major disasters can be avoided.

Benefits of Fog Computing

Fog computing provides number of benefits to business and society. Few of them are as follow:


Fog device provides services locally, availability of services increases.

Lower Operating Expense

Selected data are processed locally hence conserves network bandwidth and thus lower operating cost.

Better and Fast Decision Making:

One can analyse data locally, the way he wants. Hence, can have deeper insight into data analytics for better decision making.

Privacy Increases

Out IT team can control and monitor the devices that collect, analyse, and store sensitive data. Sensitive data can be processes and stored locally. Hence privacy data and information increases.

Better security

Same policy, controls, and procedures of own IT environment can be implemented for Fog devices. Thus it increases information / network security in addition to physical security.

Limitations of Fog Computing

  • Complex and more involved computation can’t be performed by Fog devices. Needs services from cloud server.
  • Fog device can’t provide data storage service, for storing data generated over long time duration such as month or year. It is requires to be store them on cloud server.
  • Because of heterogeneous fog network, there may be issues of compatibility.
  • If edge devices can’t get enough connectivity and bandwidth, there will be issue of latency in service.

Fog Computing, with cloud computing, artificial intelligence, Internet of Things and other supporting technologies, will surely lead to great success of smart city applications, which results into better world, in coming years.

Useful Resources on Fog Computing

  1. F. Bonomi, R. Milito, J. Zhu, and S. Addepalli. Fog computing and its role in the internet of things. In workshop on Mobile cloud computing. ACM, 2012.