High Energy Consumption Issues Research Articles

QoS provisioning and energy saving scheme for distributed cognitive radio networks using deep learning

One of the major challenges facing the realization of cognitive radios (CRs) in future mobile and wireless communications is the issue of high energy consumption. Since future network infrastructure will host real-time services requiring immediate satisfaction, the issue of high energy consumption will hinder the full realization of CRs. This means that to offer the required quality of service (QoS) in an energy-efficient manner, resource management strategies need to allow for effective trade-offs between QoS provisioning and energy saving. To address this issue, this paper focuses on single base station (BS) management, where resource consumption efficiency is obtained by solving a dynamic resource allocation (RA) problem using bipartite matching. A deep learning (DL) predictive control scheme is used to predict the traffic load for better energy saving using a stacked auto-encoder (SAE). Considered here was a base station (BS) processor with both processor sharing (PS) and first-come-first-served (FCFS) sharing disciplines under quite general assumptions about the arrival and service processes. The workload arrivals are defined by a Markovian arrival process while the service is general. The possible impatience of customers is taken into account in terms of the required delays. In this way, the BS processor is treated as a hybrid switching system that chooses a better packet scheduling scheme between mean slowdown (MS) FCFS and MS PS. The simulation results presented in this paper indicate that the proposed predictive control scheme achieves better energy saving as the traffic load increases, and that the processing of workload using MS PS achieves substantially superior energy saving compared to MS FCFS.

RETRACTED ARTICLE: Intelligent fuzzy rule-based approach with outlier detection for secured routing in WSN

In wireless sensor networks (WSNs), energy optimization and the provision of security are the major design challenges. Since the wireless sensor devices are energy constrained, the issue of high energy consumption by the malicious nodes must be addressed well in order to enhance the network performance by making increased network lifetime, reduced energy consumption and delay. In the past, many researchers worked in the provision of new techniques for providing improved security to WSN in order to enhance the reliability in the routing process. However, most of the existing routing techniques are not able to achieve the required security through the use of intelligent techniques for safeguarding the sensor nodes from malicious attacks. In order to address these problems, a new fuzzy temporal clustering-based secured communication model with trust analysis and outlier detection has been developed in this research work. For this purpose, a new fuzzy temporal rule-based cluster-based routing algorithm with trust modelling and outlier detection for monitoring the nodes participating in the communication has been proposed. In addition, a fuzzy temporal rule- and distance-based outlier detection algorithm is also proposed in this paper for distinguishing the malicious nodes from other nodes within each cluster of the network and has been used in the secured routing algorithm. The proposed secure routing algorithm uses the temporal reasoning tasks of explanation-based learning and prediction as well as spatial constraints for making efficient routing decisions through the application of trust and key management techniques for performing effective authentication of nodes and thereby isolating the malicious nodes from communication through outlier detection. By applying these two proposed algorithms for communication in the proposed work, it is proved through experiments that the proposed secure routing algorithm and the outlier detection algorithm are able to perform secured and reliable routing through genuine cluster head nodes more effectively. Moreover, these two algorithms provide improved quality of service with respect to the reliability of communication, packet delivery ratio, reduction in end-to-end delay and reduced energy consumption.

EEA

The data communication task, in wireless sensor networks (WSNs), is a major issue of high energy consumption. A hierarchical design based on a clustering algorithm is one of the approaches to manage the data communication and save energy in WSNs. However, most of the previous approaches based on clustering algorithms have not considered the length of the data communication path, which is a direct relation to energy consumption in WSNs. In this article, a novel scheme of a clustering algorithm has been proposed for reducing the data communication distance in WSNs. Hierarchical routing protocols were implemented for homogeneous and heterogeneous networks. The results show that the proposed scheme is more efficient than other protocols.

QoS-aware energy-saving mechanism for hybrid optical-wireless broadband access networks

Hybrid optical-wireless broadband access network (HOWBAN) takes full advantage of the high capacity and reliability of the passive optical network and the flexibility, ubiquity of the wireless network. Similar to other access networks, the issue of high energy consumption is a great challenge for HOWBAN. In HOWBAN, optical network units (ONUs) consume a great amount of energy. The sleep of ONUs can greatly improve the energy efficiency of HOWBAN. However, the quality of service (QoS) will be decreased while the packets are waiting in ONUs and optical line terminal. In this paper, we propose a QoS-aware energy-saving mechanism. A dynamic bandwidth allocation mechanism is designed to guarantee the QoS, where different priorities are considered. Meanwhile, we employ different sleep strategies by taking different priorities’ tolerant delays into account to prolong the sleep time of ONUs. Then, based on the evaluation of packet delay, the optimal sleep parameter is derived to maximum the energy efficiency. In addition, a load balancing and resource allocation mechanism is adopted in the wireless domain to reduce the delay and congestion caused by ONUs’ sleep. Results show that the proposed mechanism can effectively improve the energy efficiency and meet the QoS requirements of packets.

Affinity regulation of the NH3 + H2O system by ionic liquids with molecular interaction analysis.

This work proposed using an adequate ionic liquid (IL) to weaken the affinity between NH3 and H2O as a potential solution to the issue of high-energy consumption involved in separating NH3 gas from liquid H2O. Two quaternary phosphonium-based ILs were selected according to an optimized regulation strategy. The regulation effects of the ILs were evaluated by the vapor-liquid equilibrium property of the NH3 + H2O + IL systems, and were compared with the regulation effects of traditional additives. The results showed that the expected effects were achieved by adding ILs. The regulation mechanisms of different strategies were discussed with respect to the molecular structure and chemical equilibrium for the first time limited to the authors' latest literature review. Finally, the IR spectra of the NH3 + H2O + IL systems were acquired and analyzed to verify the interactions of the ILs with NH3 and H2O.

Joint Wireless and Optical Power States Scheduling for Green Multi-Radio Fiber-Wireless Access Network

Due to the massive deployment of electrical network devices, Fiber-Wireless (FiWi) access network has to suffer from the challenge of high energy consumption. With the ever-increasing eager for green communication infrastructure, the issue of high energy consumption may become one of the major barriers for the advance of FiWi access network. Previous works proposed for green FiWi access network cover three aspects, including the optimized deployment of network devices such as optical network units (ONUs), the energy-efficient bandwidth allocation of ONUs with QoS guarantee, and the dynamic power states scheduling of ONUs (i.e., active/sleep) according to their traffic profile. However, these works did not take the energy-saving design of wireless subnetwork into account simultaneously. In fact, when some ONUs in the optical subnetwork are switched into sleep states, part of the radio interfaces originally forwarding traffic to the sleep ONUs would be idle or low-loaded. This provides a potential opportunity for energy-saving in wireless subnetwork by switching off the idle or low-loaded radios. This paper focuses on the design of green multi-radio FiWi access network by integrating the energy-savings of optical and wireless subnetworks. To support the energy-efficient design, the new power states are defined for ONUs and radios, respectively. Aiming at dynamic traffic profile, the heuristic algorithms are proposed for the energy saving of integrated wireless front-end and optical back-end of FiWi access network. First, the Energy-saving algorithm with ONU sleep mechanism (EAS) is proposed to dynamically schedule the power states of ONUs by judging their traffic profile with load thresholds. Then, the Energy-saving algorithm based on Radios Off (ERO) is proposed to reconfigure the topology of wireless subnetwork by controlling the power states of radios dynamically. Moreover, wireless rerouting is employed in both EAS and ERO to guarantee the QoS provisioning ability of network. Finally, a comprehensive energy-saving scheme called EE is proposed by combining the EAS and ERO algorithms strategically. Simulation results show that with the reasonable setting of parameters, the proposed EE scheme can save the energy of 33.14% to 64.35% and 8.56% to 36.42% in a wide range of traffic load compared to the No-energy-saving and QoS-aware energy-saving scenarios, respectively.

An optimized water reuse and waste valorization method for a sustainable development of poultry slaughtering plants

The primary aim of this study is to find a solution to four of the major environmental and energy problems that currently exist in the poultry industry: (a) high water consumption, (b) emissions from excessively contaminated wastewater, (c) intensive consumption of electric and thermal energy, and (d) production of non-recoverable by-products and organic waste. It was decided that a wastewater treatment plant (WWTP) would be designed, which would, in addition to treating the water, create an effluent that meets the water quality standards, so that the water can be reused in plant processes. As part of this, a closed water circuit was created to reduce water consumption and the emission of wastewater. In order to address the issue of high-energy consumption and waste production, the construction of a biomethane production plant was proposed. Given that most of the waste is organic, the waste had to undergo anaerobic digestion processing. This resulted in biogas production, as well as subsequent use of the said biogas primarily as a thermal energy source, which was used to reduce external consumption. Both the WWTP and the biomass power plant required an anaerobic digester. The final aim of this study was to propose the implementation of a hybrid co-digestion system for wastewater and organic waste that would allow water to be treated and, at the same time, produce biogas, which could subsequently be used as an energy source.

A Water Quality Monitoring Method Based on Fuzzy Comprehensive Evaluation in Wireless Sensor Networks

A novel water quality monitoring method named WQMMFCE is proposed based on fuzzy comprehensive evaluation model to solve the issue of high energy consumption caused by centralized approach under the background of water quality monitoring. The weights of all factors which are necessary for fuzzy comprehensive evaluation can be obtained firstly by using the binary expert evaluation. The information needs to transmit is decided according to water quality grade which is quantitatively analyzed directly by using fuzzy comprehensive evaluation rather than transmitting large amount of raw data to the monitoring center. Simulation result shows that the method has a great advantage over the centralized one on energy saving and can prolong the lifetime of the network.