Edge & Fog Computing

While cloud computing has brought paradigm shifts to computing services, researchers and developers have also found some problems inherent to its nature such as bandwidth bottleneck, communication overhead, and location blindness. The concept of fog/edge computing is therefore coined to extend the services from the core in cloud data centers to the edge of the network.

Edge computing is a new computing paradigm in which substantial compute and storage resources are placed at the edge of the Internet, in close proximity to mobile devices, sensors, end users, and Internet of Things devices.

This physical proximity improves latency, bandwidth, trust, and survivability.

Fog computing is defined as “an architecture that uses edge devices to carry out a substantial amount of computation, storage, and communication” locally, as well as routed over the Internet backbone. It “most definitively has input and output from the physical world, known as transduction” (defined as the process of directly drawing conclusions about new data from previous data, without constructing a model).

Fog computing is “an architecture that uses one or a collaborative multitude of end-user clients or near-user edge devices to carry out a substantial amount of storage (rather than stored primarily in cloud data centers), communication (rather than routed over the internet backbone), and control, configuration, measurement and management (rather than controlled primarily by network gateways such as those in the LTE (telecommunication) core)”.

Edge computing is defined as "a method of optimizing applications or cloud-computing systems by taking some portion of an application, its data, or services away from one or more central nodes (the ‘core’) to the other logical extreme (the ‘edge’) of the Internet, which makes contact with the physical world or end users."

Off-loading heavy computation from devices to an edge node can reduce their power consumption and enable them to be smaller and lighter.

Various edge-computing efforts have led to technology fragmentation but also useful architectural frameworks and greater collaboration among stakeholders. LTE: Long-Term Evolution; CDN: content delivery network; u(v)CPE: universal (virtualized) customer-premises equipment; NERG: network-enhanced residential gateway; CORD: Central Office Re-architected as a Datacenter.

A hacker could learn a lot by reading data going to and from a smart-home system.

By capturing electricity or water usage, the hacker could easily determine if the house is probably vacant and thus vulnerable to burglary.

In edge computing, the cloud collects data from existing databases, as has been done traditionally, and also from end devices such as sensors and mobile phones. The devices act as both data consumers and data producers.

Thus, requests between end devices and the cloud are bidirectional, instead of just from end devices to the cloud as in the past.

Nodes at the network edge perform many computing tasks—including data processing, caching, device management, and privacy protection‑to reduce traffic from devices to the cloud.