Biblio

Several efforts are currently active in dealing with scenarios combining fog, cloud computing, out of which a significant proportion is devoted to control, and manage the resulting scenario. Certainly, although many challenging aspects must be considered towards the design of an efficient management solution, it is with no doubt that whatever the solution is, the quality delivered to the users when executing services and the security guarantees provided to the users are two key aspects to be considered in the whole design. Unfortunately, both requirements are often non-convergent, thus making a solution suitably addressing both aspects is a challenging task. In this paper, we propose a decoupled transversal security strategy, referred to as DCF, as a novel architectural oriented policy handling the QoS-Security trade-off, particularly designed to be applied to combined fog-to-cloud systems, and specifically highlighting its impact on the delivered QoS.

The cooperative spectrum leasing process between the primary user (PU) and the secondary user (SU) in a cognitive radio network under the overlay approach and the decode and forward (DF) cooperative protocol is studied. Considering the Quality of Service (QoS) provisioning of both users, which participate in a three-phase leasing process, we investigate the maximization of PU's effective capacity subject to an average energy constraint for the SU under a heuristic power and time allocation mechanism. The aforementioned proposed scheme treats with the basic concepts of the convex optimization theory and outperforms a baseline allocation mechanism which is proven by the simulations. Finally, important remarks for the PU's and the SU's performance are extracted for different system parameters.