Governing Rules: Modeling and Analysis of Task Offloading Processes in the Fog

In the previous chapters, we discussed the dissemination process of one data block, particularly its lifetime and whereabouts, in wireless networks. As data services quickly migrate to the network edge, which is composed of numerous resource-constrained wireless devices and access network elements, the dissemination processes of multiple data blocks may interfere with each other, under the competition for resources. A typical example is the emerging fog paradigm, in which a task, that is, a computation-intensive (and delay-sensitive) data block, can be offloaded to resourceful fog nodes nearby, in order to reduce latency, or save energy. The offloading decision is usually made by considering the amount of accessible resource in the network, while its execution in turn affects how other tasks will be offloaded, rendering it difficult to evaluate the performance of such large-scale fog systems.