Energy and time efficient task offloading and resource allocation on the generic IoT-fog-cloud architecture

With the exponential increase in the number of IoT devices and the amount of emitted data from these devices, it is expensive and inefficient to offload all tasks to the remote data center. How to optimize the energy consumption of application requests from IoT devices meeting the deadline constraint is also a challenge. Fog computing adjacent to users has the feature of lower service delay but less resource than the remote cloud. Fog does not appear to replace cloud, they are complementary to each other, cooperation between them is worth studying. This paper proposes a general IoT-fog-cloud architecture that fully exploits the advantages of fog and cloud. Then, the energy and time efficient computation offloading and resource allocation is formulated into the energy and time cost minimization problem. We then propose an ETCORA algorithm to solve the problem, improving the energy consumption and completion time of application requests. Finally, extensive simulations are carried out to verify that the proposed method indeed outperforms the other two methods in reducing energy consumption and completion time of requests.