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Fair rate control for wireless ad-hoc networks with time varying channel capacities
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作者 Meiqin TANG Kai MA Xinping GUAN 《控制理论与应用(英文版)》 EI 2010年第1期69-74,共6页
We consider the problem of fair rate control for wireless ad-hoc networks with time varying channel capacities. The interaction between links in wireless ad-hoc networks introduces additional constraints on the flow r... We consider the problem of fair rate control for wireless ad-hoc networks with time varying channel capacities. The interaction between links in wireless ad-hoc networks introduces additional constraints on the flow rate. A primal-dual algorithm that guarantees fair rate control is proved to be trajectory stable. Various fairness indexes are obtained by choosing the specified form of the utility functions, and the numerical results validate the effectiveness of the proposed algorithm. 展开更多
关键词 wireless ad-hoc networks Rate control Trajectory stability FAIRNESS
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Collision Avoidance in Mobile Wireless Ad-Hoc Networks with Enhanced MACAW Protocol Suite 被引量:1
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作者 Sadan Cambazoglu Arif Sari 《International Journal of Communications, Network and System Sciences》 2015年第13期533-542,共10页
Jamming attack is quite serious threat for Mobile networks that collapses all necessary communication infrastructure. Since mobile nodes in Mobile Ad Hoc Networks (MANET) communicate in a multi-hop mode, there is alwa... Jamming attack is quite serious threat for Mobile networks that collapses all necessary communication infrastructure. Since mobile nodes in Mobile Ad Hoc Networks (MANET) communicate in a multi-hop mode, there is always a possibility for an intruder to launch a jamming attack in order to intercept communication among communication nodes. In this study, a network simulation has been carried out in order to explore and evaluate the possible impacts of jamming attack on MACAW protocol. Ad-hoc network modelling is used to provide communication infrastructure among mobile nodes in order to modelling the simulation scenarios. In simulation model, these nodes have used AODV routing protocol which is designed for MANET while second scenario contains simulated MACAW node models for comparison. On the other hand, this paper is the first study that addresses performance evaluation of MACAW protocol under a constant Jamming Attack. The performance of MACAW protocol is simulated through OPNET Modeler 14.5 software. 展开更多
关键词 OPNET Simulation MACAW Mobile ad-hoc Networks COLLISION Jamming AODV
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Cluster-based Intrusion Detection in Wireless Ad-Hoc Networks
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作者 DiWu ZhishengLiu +1 位作者 YongxinFeng GuangxingWang 《计算机工程与应用》 CSCD 北大核心 2004年第29期122-125,共4页
There are inherent vulnerabilities that are not easily preventable in the mobile Ad-Hoc networks.To build a highly secure wireless Ad-Hoc network,intrusion detection and response techniques need to be deployed;The int... There are inherent vulnerabilities that are not easily preventable in the mobile Ad-Hoc networks.To build a highly secure wireless Ad-Hoc network,intrusion detection and response techniques need to be deployed;The intrusion detection and cluster-based Ad-Hoc networks has been introduced,then,an architecture for better intrusion detection based on cluster using Data Mining in wireless Ad -Hoc networks has been shown.A statistical anomaly detection approach has been used.The anomaly detection and trace analysis have been done locally in each node and possibly through cooperation with clusterhead detection in the network. 展开更多
关键词 入侵检测 移动ad-hoc网络 数据挖掘 网络安全 聚类检测
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Throughput Maximizing Frequency and Power Scheduling for Wireless Ad-Hoc Networks in the Low-SINR Regime
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作者 Nahid Saberi 《Wireless Engineering and Technology》 2012年第3期106-112,共7页
We study the problem of frequency and power allocation and scheduling at a time-slotted cognitive ad-hoc wireless network, where cognitive nodes share a number of frequency bands and frequency reuse is allowed. In suc... We study the problem of frequency and power allocation and scheduling at a time-slotted cognitive ad-hoc wireless network, where cognitive nodes share a number of frequency bands and frequency reuse is allowed. In such a network the throughput maximization problem generally results in a mixed zero-one nonlinear non-convex problem. Interestingly, in the low-SINR regime, the power allocation policy that maximizes the total throughput follows an “on/off” strategy with maximum power usage in the “on” state. In this paper we show that the on/off strategy in the low-SINR regime is also optimal with respect to throughput when scheduling users over time and frequency subject to minimum SINR requirements. We show that these additional constraints will not change the optimum strategy, but may affect the set of “on” or “off” transmitters. Also we present an approach that transforms the mixed zero-one nonlinear problem to an equivalent mixed zero-one linear problem at the expense of extra variables. 展开更多
关键词 ad-hoc NETWORKS Cognitive NETWORKS Optimization Mixed Zero-One Linear PROBLEM Zero-One Nonlinear PROBLEM
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Performance Evaluation of Queuing Management Algorithms in Hybrid Wireless Ad-Hoc Network
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作者 Ertshag Hamza Honge Ren +1 位作者 Elmustafa Sayed Xiaolong Zhu 《国际计算机前沿大会会议论文集》 2018年第1期53-53,共1页
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面向Ad-Hoc协作的局部观测重建方法
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作者 陈皓 杨立昆 +1 位作者 尹奇跃 黄凯奇 《中国科学院大学学报(中英文)》 CSCD 北大核心 2024年第1期117-126,共10页
在多智能体强化学习的研究中,如何进行Ad-Hoc协作,也就是说如何适应种类和数量变化的队友,是一个关键问题。现有方法或者有很强的先验知识假设,或者使用硬编码的规则进行合作,缺乏通用性,无法泛化到更一般的Ad-Hoc协作场景。为解决该问... 在多智能体强化学习的研究中,如何进行Ad-Hoc协作,也就是说如何适应种类和数量变化的队友,是一个关键问题。现有方法或者有很强的先验知识假设,或者使用硬编码的规则进行合作,缺乏通用性,无法泛化到更一般的Ad-Hoc协作场景。为解决该问题,提出一种面向Ad-Hoc协作的局部观测重建算法,利用注意力机制和采样网络对局部观测进行重建,使得算法认识到并充分利用不同局面中的高维状态表征,实现了在Ad-Hoc协作场景下的零样本泛化。在星际争霸微操环境和Ad-Hoc协作场景上与代表性算法的性能进行对比与分析,验证了算法的有效性。 展开更多
关键词 多智能体 深度强化学习 信用分配 ad-hoc协作
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Highlights in recent wireless power IC research
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作者 Cheng Huang Junyao Tang 《Journal of Semiconductors》 EI CAS CSCD 2024年第4期5-7,共3页
Wireless power transfer(WPT)has been a popular topic in power integrated circuit(IC)designs in the past decade.As slogan"cutting the last wire"presented in ISSCC’15[1],WPT is poised to take over many wired ... Wireless power transfer(WPT)has been a popular topic in power integrated circuit(IC)designs in the past decade.As slogan"cutting the last wire"presented in ISSCC’15[1],WPT is poised to take over many wired power deliveries applica-tions today,just like what happened to wireless communica-tion nowadays.Over the years,WPT has become more mature and more wirelessly charged or powered products have become available on the market.This mini review intends to summarize recent breakthroughs in WPT inte-grated circuits(IC)research. 展开更多
关键词 WPT POWER wireless
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Intelligent Reflecting Surface Assisted Transmission Optimization Strategies in Wireless Networks
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作者 He Xinxin Qi Xuan +2 位作者 Meng Wei Liu Wei Yin Changchuan 《China Communications》 SCIE CSCD 2024年第4期120-135,共16页
Wireless Power Transfer(WPT)technology can provide real-time power for many terminal devices in Internet of Things(IoT)through millimeterWave(mmWave)to support applications with large capacity and low latency.Although... Wireless Power Transfer(WPT)technology can provide real-time power for many terminal devices in Internet of Things(IoT)through millimeterWave(mmWave)to support applications with large capacity and low latency.Although the intelligent reflecting surface(IRS)can be adopted to create effective virtual links to address the mmWave blockage problem,the conventional solutions only adopt IRS in the downlink from the Base Station(BS)to the users to enhance the received signal strength.In practice,the reflection of IRS is also applicable to the uplink to improve the spectral efficiency.It is a challenging to jointly optimize IRS beamforming and system resource allocation for wireless energy acquisition and information transmission.In this paper,we first design a Low-Energy Adaptive Clustering Hierarchy(LEACH)clustering protocol for clustering and data collection.Then,the problem of maximizing the minimum system spectral efficiency is constructed by jointly optimizing the transmit power of sensor devices,the uplink and downlink transmission times,the active beamforming at the BS,and the IRS dynamic beamforming.To solve this non-convex optimization problem,we propose an alternating optimization(AO)-based joint solution algorithm.Simulation results show that the use of IRS dynamic beamforming can significantly improve the spectral efficiency of the system,and ensure the reliability of equipment communication and the sustainability of energy supply under NLOS link. 展开更多
关键词 intelligent reflecting surface(IRS) joint optimization millimeter wave wireless information transmission(WIT) wireless power transfer(WPT)
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Collaborative positioning for swarms:A brief survey of vision,LiDAR and wireless sensors based methods
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作者 Zeyu Li Changhui Jiang +3 位作者 Xiaobo Gu Ying Xu Feng zhou Jianhui Cui 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期475-493,共19页
As positioning sensors,edge computation power,and communication technologies continue to develop,a moving agent can now sense its surroundings and communicate with other agents.By receiving spatial information from bo... As positioning sensors,edge computation power,and communication technologies continue to develop,a moving agent can now sense its surroundings and communicate with other agents.By receiving spatial information from both its environment and other agents,an agent can use various methods and sensor types to localize itself.With its high flexibility and robustness,collaborative positioning has become a widely used method in both military and civilian applications.This paper introduces the basic fundamental concepts and applications of collaborative positioning,and reviews recent progress in the field based on camera,LiDAR(Light Detection and Ranging),wireless sensor,and their integration.The paper compares the current methods with respect to their sensor type,summarizes their main paradigms,and analyzes their evaluation experiments.Finally,the paper discusses the main challenges and open issues that require further research. 展开更多
关键词 Collaborative positioning VISION LIDAR wireless sensors Sensor fusion
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A Fuzzy Trust Management Mechanism with Dynamic Behavior Monitoring for Wireless Sensor Networks
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作者 Fu Shiming Zhang Ping Shi Xuehong 《China Communications》 SCIE CSCD 2024年第5期177-189,共13页
Traditional wireless sensor networks(WSNs)are typically deployed in remote and hostile environments for information collection.The wireless communication methods adopted by sensor nodes may make the network highly vul... Traditional wireless sensor networks(WSNs)are typically deployed in remote and hostile environments for information collection.The wireless communication methods adopted by sensor nodes may make the network highly vulnerable to various attacks.Traditional encryption and authentication mechanisms cannot prevent attacks launched by internal malicious nodes.The trust-based security mechanism is usually adopted to solve this problem in WSNs.However,the behavioral evidence used for trust estimation presents some uncertainties due to the open wireless medium and the inexpensive sensor nodes.Moreover,how to efficiently collect behavioral evidences are rarely discussed.To address these issues,in this paper,we present a trust management mechanism based on fuzzy logic and a cloud model.First,a type-II fuzzy logic system is used to preprocess the behavioral evidences and alleviate uncertainty.Then,the cloud model is introduced to estimate the trust values for sensor nodes.Finally,a dynamic behavior monitoring protocol is proposed to provide a balance between energy conservation and safety assurance.Simulation results demonstrate that our trust management mechanism can effectively protect the network from internal malicious attacks while enhancing the energy efficiency of behavior monitoring. 展开更多
关键词 behavior monitoring CLOUD FUZZY TRUST wireless sensor networks
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Rao Algorithms-Based Structure Optimization for Heterogeneous Wireless Sensor Networks
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作者 Shereen K.Refaay Samia A.Ali +2 位作者 Moumen T.El-Melegy Louai A.Maghrabi Hamdy H.El-Sayed 《Computers, Materials & Continua》 SCIE EI 2024年第1期873-897,共25页
The structural optimization of wireless sensor networks is a critical issue because it impacts energy consumption and hence the network’s lifetime.Many studies have been conducted for homogeneous networks,but few hav... The structural optimization of wireless sensor networks is a critical issue because it impacts energy consumption and hence the network’s lifetime.Many studies have been conducted for homogeneous networks,but few have been performed for heterogeneouswireless sensor networks.This paper utilizes Rao algorithms to optimize the structure of heterogeneous wireless sensor networks according to node locations and their initial energies.The proposed algorithms lack algorithm-specific parameters and metaphorical connotations.The proposed algorithms examine the search space based on the relations of the population with the best,worst,and randomly assigned solutions.The proposed algorithms can be evaluated using any routing protocol,however,we have chosen the well-known routing protocols in the literature:Low Energy Adaptive Clustering Hierarchy(LEACH),Power-Efficient Gathering in Sensor Information Systems(PEAGSIS),Partitioned-based Energy-efficient LEACH(PE-LEACH),and the Power-Efficient Gathering in Sensor Information Systems Neural Network(PEAGSIS-NN)recent routing protocol.We compare our optimized method with the Jaya,the Particle Swarm Optimization-based Energy Efficient Clustering(PSO-EEC)protocol,and the hybrid Harmony Search Algorithm and PSO(HSA-PSO)algorithms.The efficiencies of our proposed algorithms are evaluated by conducting experiments in terms of the network lifetime(first dead node,half dead nodes,and last dead node),energy consumption,packets to cluster head,and packets to the base station.The experimental results were compared with those obtained using the Jaya optimization algorithm.The proposed algorithms exhibited the best performance.The proposed approach successfully prolongs the network lifetime by 71% for the PEAGSIS protocol,51% for the LEACH protocol,10% for the PE-LEACH protocol,and 73% for the PEGSIS-NN protocol;Moreover,it enhances other criteria such as energy conservation,fitness convergence,packets to cluster head,and packets to the base station. 展开更多
关键词 wireless sensor networks Rao algorithms OPTIMIZATION LEACH PEAGSIS
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Mechanism analysis of regulating Turing instability and Hopf bifurcation of malware propagation in mobile wireless sensor networks
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作者 黄习习 肖敏 +3 位作者 Leszek Rutkowski 包海波 黄霞 曹进德 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期125-140,共16页
A dynamical model is constructed to depict the spatial-temporal evolution of malware in mobile wireless sensor networks(MWSNs). Based on such a model, we design a hybrid control scheme combining parameter perturbation... A dynamical model is constructed to depict the spatial-temporal evolution of malware in mobile wireless sensor networks(MWSNs). Based on such a model, we design a hybrid control scheme combining parameter perturbation and state feedback to effectively manipulate the spatiotemporal dynamics of malware propagation. The hybrid control can not only suppress the Turing instability caused by diffusion factor but can also adjust the occurrence of Hopf bifurcation induced by time delay. Numerical simulation results show that the hybrid control strategy can efficiently manipulate the transmission dynamics to achieve our expected desired properties, thus reducing the harm of malware propagation to MWSNs. 展开更多
关键词 mobile wireless sensor networks REACTION-DIFFUSION Hopf bifurcation hybrid control
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Enhancing Wireless Sensor Network Efficiency through Al-Biruni Earth Radius Optimization
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作者 Reem Ibrahim Alkanhel Doaa Sami Khafaga +4 位作者 Ahmed Mohamed Zaki Marwa M.Eid Abdyalaziz A.Al-Mooneam Abdelhameed Ibrahim S.K.Towfek 《Computers, Materials & Continua》 SCIE EI 2024年第6期3549-3568,共20页
The networks of wireless sensors provide the ground for a range of applications,including environmental moni-toring and industrial operations.Ensuring the networks can overcome obstacles like power and communication r... The networks of wireless sensors provide the ground for a range of applications,including environmental moni-toring and industrial operations.Ensuring the networks can overcome obstacles like power and communication reliability and sensor coverage is the crux of network optimization.Network infrastructure planning should be focused on increasing performance,and it should be affected by the detailed data about node distribution.This work recommends the creation of each sensor’s specs and radius of influence based on a particular geographical location,which will contribute to better network planning and design.By using the ARIMA model for time series forecasting and the Al-Biruni Earth Radius algorithm for optimization,our approach bridges the gap between successive terrains while seeking the equilibrium between exploration and exploitation.Through implementing adaptive protocols according to varying environments and sensor constraints,our study aspires to improve overall network operation.We compare the Al-Biruni Earth Radius algorithm along with Gray Wolf Optimization,Particle Swarm Optimization,Genetic Algorithms,and Whale Optimization about performance on real-world problems.Being the most efficient in the optimization process,Biruni displays the lowest error rate at 0.00032.The two other statistical techniques,like ANOVA,are also useful in discovering the factors influencing the nature of sensor data and network-specific problems.Due to the multi-faceted support the comprehensive approach promotes,there is a chance to understand the dynamics that affect the optimization outcomes better so decisions about network design can be made.Through delivering better performance and reliability for various in-situ applications,this research leads to a fusion of time series forecasters and a customized optimizer algorithm. 展开更多
关键词 wireless sensor networks OPTIMIZATION ARIMA model BER algorithm metaheuristic algorithms
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Advances in Wireless,Batteryless,Implantable Electronics for Real‑Time,Continuous Physiological Monitoring
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作者 Hyeonseok Kim Bruno Rigo +2 位作者 Gabriella Wong Yoon Jae Lee Woon‑Hong Yeo 《Nano-Micro Letters》 SCIE EI CSCD 2024年第3期254-302,共49页
This review summarizes recent progress in developing wireless,batteryless,fully implantable biomedical devices for real-time continuous physiological signal monitoring,focusing on advancing human health care.Design co... This review summarizes recent progress in developing wireless,batteryless,fully implantable biomedical devices for real-time continuous physiological signal monitoring,focusing on advancing human health care.Design considerations,such as biological constraints,energy sourcing,and wireless communication,are discussed in achieving the desired performance of the devices and enhanced interface with human tissues.In addition,we review the recent achievements in materials used for developing implantable systems,emphasizing their importance in achieving multi-functionalities,biocompatibility,and hemocompatibility.The wireless,batteryless devices offer minimally invasive device insertion to the body,enabling portable health monitoring and advanced disease diagnosis.Lastly,we summarize the most recent practical applications of advanced implantable devices for human health care,highlighting their potential for immediate commercialization and clinical uses. 展开更多
关键词 Implantable electronics Biomedical systems Batteryless devices wireless electronics Physiological signal monitoring
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A Practical Approach for Missing Wireless Sensor Networks Data Recovery
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作者 Song Xiaoxiang Guo Yan +1 位作者 Li Ning Ren Bing 《China Communications》 SCIE CSCD 2024年第5期202-217,共16页
In wireless sensor networks(WSNs),the performance of related applications is highly dependent on the quality of data collected.Unfortunately,missing data is almost inevitable in the process of data acquisition and tra... In wireless sensor networks(WSNs),the performance of related applications is highly dependent on the quality of data collected.Unfortunately,missing data is almost inevitable in the process of data acquisition and transmission.Existing methods often rely on prior information such as low-rank characteristics or spatiotemporal correlation when recovering missing WSNs data.However,in realistic application scenarios,it is very difficult to obtain these prior information from incomplete data sets.Therefore,we aim to recover the missing WSNs data effectively while getting rid of the perplexity of prior information.By designing the corresponding measurement matrix that can capture the position of missing data and sparse representation matrix,a compressive sensing(CS)based missing data recovery model is established.Then,we design a comparison standard to select the best sparse representation basis and introduce average cross-correlation to examine the rationality of the established model.Furthermore,an improved fast matching pursuit algorithm is proposed to solve the model.Simulation results show that the proposed method can effectively recover the missing WSNs data. 展开更多
关键词 average cross correlation matching pursuit missing data wireless sensor networks
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Ultraconformable Integrated Wireless Charging Micro-Supercapacitor Skin
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作者 Chang Gao Qing You +5 位作者 Jiancheng Huang Jingye Sun Xuan Yao Mingqiang Zhu Yang Zhao Tao Deng 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第7期46-58,共13页
Conformable and wire-less charging energy storage devices play important roles in enabling the fast development of wearable,non-contact soft electronics.However,current wire-less charging power sources are still restr... Conformable and wire-less charging energy storage devices play important roles in enabling the fast development of wearable,non-contact soft electronics.However,current wire-less charging power sources are still restricted by limited flexural angles and fragile connection of components,resulting in the failure expression of performance and constraining their fur-ther applications in health monitoring wearables and moveable artificial limbs.Herein,we present an ultracompatible skin-like integrated wireless charging micro-supercapacitor,which building blocks(including electrolyte,electrode and substrate)are all evaporated by liquid precursor.Owing to the infiltration and permeation of the liquid,each part of the integrated device attached firmly with each other,forming a compact and all-in-one configuration.In addition,benefitting from the controllable volume of electrode solution precursor,the electrode thickness is easily regulated varying from 11.7 to 112.5μm.This prepared thin IWC-MSC skin can fit well with curving human body,and could be wireless charged to store electricity into high capacitive micro-supercapacitors(11.39 F cm-3)of the integrated device.We believe this work will shed light on the construction of skin-attachable electronics and irregular sensing microrobots. 展开更多
关键词 Micro-supercapacitor Electronic skin Supercapacitor skin wireless charging energy storage device
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Stackelberg Game for Wireless Powered and Backscattering Enabled Sensor Networks
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作者 Lyu Bin Cao Yi +2 位作者 Wang Shuai Guo Haiyan Hao Chengyao 《China Communications》 SCIE CSCD 2024年第3期189-204,共16页
This paper investigates a wireless powered and backscattering enabled sensor network based on the non-linear energy harvesting model, where the power beacon(PB) delivers energy signals to wireless sensors to enable th... This paper investigates a wireless powered and backscattering enabled sensor network based on the non-linear energy harvesting model, where the power beacon(PB) delivers energy signals to wireless sensors to enable their passive backscattering and active transmission to the access point(AP). We propose an efficient time scheduling scheme for network performance enhancement, based on which each sensor can always harvest energy from the PB over the entire block except its time slots allocated for passive and active information delivery. Considering the PB and wireless sensors are from two selfish service providers, we use the Stackelberg game to model the energy interaction among them. To address the non-convexity of the leader-level problem, we propose to decompose the original problem into two subproblems and solve them iteratively in an alternating manner. Specifically, the successive convex approximation, semi-definite relaxation(SDR) and variable substitution techniques are applied to find a nearoptimal solution. To evaluate the performance loss caused by the interaction between two providers, we further investigate the social welfare maximization problem. Numerical results demonstrate that compared to the benchmark schemes, the proposed scheme can achieve up to 35.4% and 38.7% utility gain for the leader and the follower, respectively. 展开更多
关键词 backscatter communication energy interaction stackelberg game wireless powered sensor network
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A blockchain-empowered authentication scheme for worm detection in wireless sensor network
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作者 Yuling Chen Xiong Yang +2 位作者 Tao Li Yi Ren Yangyang Long 《Digital Communications and Networks》 SCIE CSCD 2024年第2期265-272,共8页
Wireless Sensor Network(WSN)is a distributed sensor network composed a large number of nodes with low cost,low performance and self-management.The special structure of WSN brings both convenience and vulnerability.For... Wireless Sensor Network(WSN)is a distributed sensor network composed a large number of nodes with low cost,low performance and self-management.The special structure of WSN brings both convenience and vulnerability.For example,a malicious participant can launch attacks by capturing a physical device.Therefore,node authentication that can resist malicious attacks is very important to network security.Recently,blockchain technology has shown the potential to enhance the security of the Internet of Things(IoT).In this paper,we propose a Blockchain-empowered Authentication Scheme(BAS)for WSN.In our scheme,all nodes are managed by utilizing the identity information stored on the blockchain.Besides,the simulation experiment about worm detection is executed on BAS,and the security is evaluated from detection and infection rate.The experiment results indicate that the proposed scheme can effectively inhibit the spread and infection of worms in the network. 展开更多
关键词 wireless Sensor Network(WSN) Node authentication Blockchain TANGLE Worm detection
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Wireless Positioning:Technologies,Applications,Challenges,and Future Development Trends
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作者 Xingwang Li Hua Pang +4 位作者 Geng Li Junjie Jiang Hui Zhang Changfei Gu Dong Yuan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1135-1166,共32页
The development of the fifth-generation(5G)mobile communication systems has entered the commercialization stage.5G has a high data rate,low latency,and high reliability that can meet the basic demands of most industri... The development of the fifth-generation(5G)mobile communication systems has entered the commercialization stage.5G has a high data rate,low latency,and high reliability that can meet the basic demands of most industries and daily life,such as the Internet of Things(IoT),intelligent transportation systems,positioning,and navigation.The continuous progress and development of society have aroused wide concern.Positioning accuracy is the core demand for the applications,especially in complex environments such as airports,warehouses,supermarkets,and basements.However,many factors also affect the accuracy of positioning in those environments,for example,multipath effects,non-line-of-sight,and clock synchronization errors.This paper provides a comprehensive review of the existing works about positioning for the future wireless network and discusses its key techniques and algorithms,as well as the current development and future directions.We first outline the current traditional positioning technologies and algorithms,which are discussed and analyzed with the relevant literature.In addition,we also discuss application scenarios for wireless localization.By comparing different positioning systems,the challenges and future development directions of existing wireless positioning systems are prospected. 展开更多
关键词 5G wireless positioning reconfigurable intelligent surface Internet of Vehicles
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Wireless Power Supply Based on MNG-MNZ Metamaterial for Cardiac Pacemakers
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作者 Weihua Chen Jingtao Jia +2 位作者 Xiaoheng Yan Yuhang Song Jiayi Li 《CES Transactions on Electrical Machines and Systems》 EI CSCD 2024年第1期103-112,共10页
To solve the low power transfer efficiency and magnetic field leakage problems of cardiac pacemaker wireless powering, we proposed a wireless power supply system suitable for implanted cardiac pacemaker based on mu-ne... To solve the low power transfer efficiency and magnetic field leakage problems of cardiac pacemaker wireless powering, we proposed a wireless power supply system suitable for implanted cardiac pacemaker based on mu-negative(MNG) and mu-nearzero(MNZ) metamaterials. First, a hybrid metamaterial consisted of central MNG unit for magnetic field concentration and surrounding MNZ units for magnetic leakage shielding was established by theoretical calculation. Afterwards, the magnetic field distribution of wireless power supply system with MNG-MNZ metamaterial slab was acquired via finite element simulation and verified to be better than the distribution with conventional MNG slab deployed. Finally, an experimental platform of wireless power supply system was established with which power transfer experiment and system temperature rise experiment were conducted.Simulation and experimental results showed that the power transfer efficiency was improved from 44.44%,19.42%, 8.63% and 6.19% to 55.77%, 62.39%, 20.81%and 14.52% at 9.6 mm, 20 mm, 30 mm and 50 mm,respectively. The maximum SAR acquired by SAR simulation under human body environment was-7.14 dbm and maximum reduction of the magnetic field strength around the receiving coil was 2.82 A/m. The maximum temperature rise during 30min charging test was 3.85℃,and the safety requirements of human bodies were met. 展开更多
关键词 Cardiac pacemaker MNG metamaterial MNZ metamaterial wireless power supply system
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