Fog computing plays a significant role in the next generation of mobile networks (5G) in support of the IoT.
Various applications can make use of different services introduced by fog technology to enhance the overall performance of the network. In this section, we describe and list some typical ones of these applications. Figure
3 illustrates various applications of fog computing in support of the IoT.
Agriculture is a vital part of any sustainable smart city projects as it contributes to the food supply chain significantly. In the smart agriculture domain, sensors deployed in field vehicles can be used to collect
information regarding the plant growth and climate conditions in the field. In addition, air balloons can be utilized to sense the field from the sky. Fog computing can play an important role in doing the aforementioned
sensing tasks more efficiently. For example, in, a fog computing-based solution is proposed for the smart agriculture where the computing is distributed to balance the computational load and reduce the waiting time in the actuation phase of an event. The infrastructure can easily manage agricultural lands and track the alarm notifications from the sensor nodes.
Smart Traffic Light and Intelligent Transportation Systems (ITS)
A smart traffic light system is a network of connected traffic lights which helps to minimize traffic congestion, prevent accidents and reduce noise and fuel consumption. This, in turn, can provide a better driving experience
for people. For example, in case of health monitoring systems, street cameras that sense the flashing lights of an ambulance can change the street-lights for the ambulance to pass through the traffic. In this domain, street-lights communicate with sensors and detect the presence of vehicles and pedestrians, and adjust the lighting accordingly. Fog devices can coordinate to provide green traffic wave and send warning signals to vehicles approaching the traffic. Moreover, in the context of ITSs, transportation data would be huge and can cause large delays if a central system is responsible to analyze the data. In this regard, fog-based devices placed at certain intersections can be used to analyze local data and inform people of the updated information about the routes which in turn reduces the delay significantly.
Fog computing can be utilized in the healthcare domain in which it is crucial to perform processes in real-time. For instance, fog technology can be used to detect, predict, and prevent falls for stroke patients. In, a pervasive fall detection for stroke mitigation is employed for similar purposes using fog computing technology to investigate and develop new algorithms for designing a real-time fall detection system based on new filtering and non-linear time series analysis techniques. Experimental results show that using fog computing improves the performance of the system in terms of response time and energy consumption compared to cloud-only approaches. Moreover, a fog-based smart healthcare system provides mobility support, low latency, and location and privacy awareness.
Smart Water Management
One of the most important aspects regarding future sustainable smart cities is related to smart water management. Cost-effective and energy-efficient transportation and use of water are important in this regard.
A smart water management system helps to monitor water consumption, transportation, and anticipation of future water use. In addition to all of these features, the smart water management system can reduce water
losses in the city and improve the city water system by analyzing data collected from the sensors deployed in Journal Pre-proof
the system. In this regard, fog-based infrastructures together with other wireless technologies and protocols such as IPv6, 3G, 4G, and LTE will help to achieve the mentioned enhancement in the smart city’s water system.
Moreover, fog computing can enhance the Cloud of Things (CoT) services which can be utilized to implement smart water networks in order to make them more sustainable, more reliable and more efficient. In
addition, the CoT with the help of fog technology can monitor the quality of water, and provide information on the presence of toxins or pollutants in the water in real-time.
In sustainable smart cities, smart grids are important since they provide efficiency, availability, and reliability in electricity management in the city . A smart grid system is expected to improve the transmission efficiency of electricity, minimize operation costs, and provide better integration with renewable energy systems in order to save electricity for future usage. Therefore, it will be of great importance to build better electricity networks and reduce the electricity bills in the cities. In this regard, fog computing plays a significant role in the support of a successful smart grid in smart cities. In a fog-based smart grid, data generated by fog devices and sensors can be processed by fog collectors. They can also filter the data to be locally processed and send it to the cloud for real-time visualization and analysis. For example, the study in proposes a fog-based architecture for Transactive Energy (TE) management system where fog nodes are used as retail energy market\ server providing energy services to the users. In the proposed architecture, customers avoid buying energy from the power grid which is more expensive at peak times and instead, buy energy from each other. The performance evaluation of the proposed architecture reveals that the fog-based architecture outperforms the cloud-based model in terms of total bandwidth and delay especially when the communication channel is not ideal.