I recently saw a very interesting presentation, - From Cloud to Fog: The Internet of Things, - by Cisco executive Michael Enescu. He tells us that the Internet of Things (IoT) is truly taking off, already comprising about 25 billion smart devices at the edges of the Internet, a number that’s expected to more than double over the next decade, and continue to keep growing for the foreseeable future.
These devices generate massive amounts of data, a lot of which requires real-time actions. It’s impractical to move all that data to a central cloud for analysis and actions. Computing and intelligence thus have to move closer to the edge, to both ameliorate the data transport challenges and enable real-time actions as required. This all leads to what has come to be known as edge computing, - an architectural bridge between the clouds at the center and the IoT devices all around the edges of the Internet. Cisco calls it fog computing, an allusion to what happens to clouds as they get closer to the ground.
Cisco defines fog computing as “a highly virtualized platform that provides compute, storage, and networking services between end devices and traditional Cloud Computing Data Centers, typically, but not exclusively located at the edge of network.” Fog complements cloud with a number of important capabilities, including edge location awareness, low latency in highly constrained connectivity environments, bandwidth and energy optimizations, and nearly unlimited scale.
Enescu notes that cloud and fog represent two very different IoT paradigms for dealing with huge amounts of data. In cloud, the data generated by the smart sensors at the edges is transferred and stored in the center, where it’s analyzed, and the appropriate actions then flow back across the network. With fog on the other hand, the analysis is done in real time at or near the edge devices, from which actions then flow across the network, with only the data to be stored being transferred to the central cloud.