论文名：A Comprehensive Survey on Fog Computing State-of-the-Art and Research Challenges
来源：IEEE Communications Surveys & Tutorials
Link: https://ieeexplore.ieee.org/abstract/document/8100873/
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The prospect of fog computing: Tactile Internet
Fog computing is suitable for: Internet of Things, Internet of Vehicles, Content Interaction (CDN), Car Ad Hoc Network (VANET), Radio Access Network (RAN)
Fog computing is a supplement to cloud computing
Cyber Foraging: Proposed in 2002. Assigning tasks such as computing and storage on mobile terminals with limited resources to the computing and storage servers near the terminal equipment can reduce the amount of calculations on the mobile terminal and improve the performance of the terminal
Cloudlet: Proposed in 2009. Using cloudlet, the face detection and matching process will be performed on the VM instead of the real machine. With the help of VM technology, cloudlet can dynamically expand and contract, thereby finally achieving scalability for mobile user service requests. VM separates the guest software environment from the host software environment of cloudlet, which improves compatibility. Although Cloudlet represents the middle layer of the three-tier architecture (ie mobile device-Cloudlet-Cloud), in the current definition of Cloudlet, there is no special focus on the interaction with Cloud. Cloudlet can also act as a complete cloud on the edge. Even if they are completely isolated from the cloud, they can also exist as independent environments because the VM provisioning of Cloudlet can be completed without cloud intervention.
Radio Access Network (RAN): It is a part of the mobile communication system. It is the realization of Radio Access Technology (RAT, Radio Access Technology). Conceptually, it exists between a device (for example, a mobile phone, a computer, or any machine that is remotely controlled) and a core network (Core Network, referred to as CN), providing a communication connection between the two. According to different standards, mobile phones and other wirelessly connected devices have different names, such as "User Equipment" (UE), Terminal Equipment (Terminal Equipment), and Mobile Station (MS). )and many more.
The position of RAN in the network is shown in the following figure:
CN
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RAN RAN
/ \ / \
UE UE UE UE
Multi-access Edge Computing (MEC): Proposed in 2014. At the beginning, I focused on mobile network and VM virtualization technology. In 2017, the scope was expanded to include non-mobile networks and virtualization technologies other than VMs. It communicates with mobile devices at the edge, not the cloud. Before range expansion, the concept (conceived as a key technology for 5G) aims to provide cloud computing functions at the edge of mobile networks and within the radio access network (RAN). These functions are provided by mobile edge computing servers, which can be deployed at LTE base station (eNodeB) sites, 3G radio network controller (RNC) sites, and multi-radio access technology (RAT) sites. Envisaged applications include augmented reality, intelligent video acceleration and connected cars. Due to the new scope, the edge of non-mobile networks and related applications will definitely be considered now.
Fog Computing: Proposed in 2012. It is an extension of the cloud computing paradigm from the core to the edge of the network. It allows you to perform calculations at the edge of the network, closer to the IoT and/or end user equipment. It also supports virtualization. However, unlike cloudlet and MEC, fog is closely related to the existence of clouds, that is, fog cannot operate in a standalone mode.
The difference between Cloudlet, MEC and Fog:
To be continued. . .