Cross-Cloud Federation (CCF) enables resource exchange among multiple, heterogeneous Cloud Service Providers (CSPs) to support the composition of services (workflow) hosted by different providers. CCF participation can either be fixed, or the types of services that can be used are limited to reduce the potential risk of service failure or secure access. Although many service selection approaches have been proposed in literature for cloud computing, their applicability to CCF i.e., cloud-to-cloud interaction, has not been adequately investigated. A key component of this cloud-to-cloud paradigm involves assessing the combined capability of contributing participants within a federation and their connectivity. A novel Aggregated Capability Assessment (AgCA) approach based on using the Consensus Assessment Initiative Questionnaire from Cloud Security Alliance is proposed for CCF. The proposed mechanism is implemented as a component of a centralized broker to enhance the quality of the selection process for participants within a federation. Our experimental results show thatAgCAis a useful tool for partner selection in a dynamic, heterogeneous and multilevel cloud federation.

In this article, we investigate the wireless power transfer and energy-efficiency (EE) optimization problem for nano-empowered vehicular networks operating over the terahertz band. The nano-sensors in air can harvest energy from a power station and then can transmit the trace information to the micro-device under reconnaissance vehicular scenarios. Hence, by considering the properties of the terahertz band, we develop a long-term EE optimization problem. Furthermore, with the help of the equivalent transformation method, we converted the EE optimization problem into a series of energy-efficient resource allocation problems over the time slots. Each reformulated optimization problem becomes a mixed integer nonlinear programming (MINLP) over a time slot. Hence, to obtain the sub-optimal solution of the reformulated optimization problem, we developed a Quantum-behaved Particle swarm-based EE Optimization (QPEEO) algorithm. Furthermore, by exploiting the special structure of the reformulated problem, we propose an Improved Discrete Particle swarm-based EE Optimization (IDPEEO) algorithm. The proposed IDPEEO algorithm handles the problem's constraints effectively, and greatly reduces the search space and the convergence time. Our simulation results validate the theoretical analysis of the proposed scheme.

Recently, nodes cooperation has emerged as a popular means for improving the quality of multimedia delivery over fifth‐generation cellular networks. However, in the conventional relaying scheme such as amplify‐and‐forward (AaF), there is a higher probability of duplicate packets at the receiver node which affect the decoding probability and consequently deteriorate the quality of multimedia transmission. In this study, the authors propose a cooperative multimedia transmission protocol based on a novel merge‐and‐forward relaying and the best relay selection (RS) schemes. Their best RS scheme is based on two important parameters: (i) two‐hop link distances and (ii) minimum block error rate value. Moreover, to combat the packet loss for enhanced and reliable video delivery, they adopt application layer forward error correction scheme which is based on the most improved and advanced version of fountain codes (i.e. RaptorQ codes). They evaluate the performance of the proposed scheme under different time‐sharing scenarios between the direct and best indirect transmission links in terms of decoding failure probability, decoding overhead, peak signal‐to‐noise ratio, and mean opinion score. Simulation results show that the proposed scheme outperforms the conventional AaF relaying scheme.

A distance based power control scheme is proposed and developed for application-controlled handover (ACH) in wireless personal area network (WPAN). In this paper, a power efficient communications in the wired wireless synergy network environment that consists of 3G (UMTS) + WiMAX + WLAN + WPAN (UWB) and optical network has been developed. This paper presents an enhanced power controlled transmission mechanism, which maintains the channel and the seamless transmission from mobile device to the remote optical fibre network, to provide real time service continuity for multimedia traffic with minimum power consumption. The results have proven the system performance improvements in the network throughput, the average data drop has been reduced 40% and the end-to-end network power consumption is reduced 10% when the proposed approach is applied on ACH based WPAN.