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The details of edge computing architecture could be different in different contexts. For example, Chen et al. [14] propose an edge computing architecture for IoT-based manufacturing. The role of edge computing is analyzed with respect to edge equipment, network communication, information fusion, and cooperative mechanism with cloud computing. Zhang et al. [15] proposes the edge-based architecture and implementation for a smart home. The system consists of three distinct layers: the sensor layer, the edge layer, and the cloud layer.

Generally speaking, Wei Yu et al. divides the structure of edge computing into three aspects: the front-end, near-end, and far-end (see Figure 2.2). A detailed description is given below:

 The front end consists of heterogeneous end devices (e.g. smartphones, sensors, actuators), which are deployed at the front end of the edge computing structure. This layer provides real-time responsiveness and local authority for the end-users. Nevertheless, the front-end environment provides more interaction by keeping the heaviest traffic and processing closest to the end-user devices. However, due to the limited resource capabilities provided by end devices, it is clear that not all requirements can be met by this layer. Thus, in such situations, the end devices must forward the resource requirements to the more powerful devices, such as fog node or cloud computing data centers.

 The near end will support most of the traffic flows in the networks. This layer provides more powerful devices, which means that most of the data processing and storage will be migrated to the near-end environment. Additionally, many tasks like caching, device management, and privacy protection can be deployed at this layer. By increasing the distance between the source of data and its processing destination (e.g. fog node) it also increases the latency due to the round-trip journey. However, the latency is very low since the devices are one hop away from the source where the data is produced and consumed.Figure 2.2 An overview of edge computing architecture [16]. (See color plate section for the color representation of this figure)

 The far end environment is cloud servers that are deployed farther away from the end devices. This layer provides devices with high processing capabilities and more data storage. Additionally, it can be configured to provide levels of performance, security, and control for both users and service providers. Nevertheless, the far-end layer enables any user to access unimaginable computing power where thousands of servers may be orchestrated to focus on the task, such as in [17, 18]. However, one must note that the transmission latency is increased in the networks by increasing the distance that data has to travel.