Multiway Relay Based Framework for Network Coding in Multi-Hop WSNs

In today’s information technology(IT)world,the multi-hop wireless sensor networks(MHWSNs)are considered the building block for the Internet of Things(IoT)enabled communication systems for controlling everyday tasks of organizations and industry to provide quality of service(QoS)in a stipulated time slot to end-user over the Internet.Smart city(SC)is an example of one such application which can automate a group of civil services like automatic control of traffic lights,weather prediction,surveillance,etc.,in our daily life.These IoT-based networks with multi-hop communication and multiple sink nodes provide efficient communication in terms of performance parameters such as throughput,energy efficiency,and end-to-end delay,wherein low latency is considered a challenging issue in next-generation networks(NGN).This paper introduces a single and parallels stable server queuing model with amulti-class of packets and native and coded packet flowto illustrate the simple chain topology and complexmultiway relay(MWR)node with specific neighbor topology.Further,for improving data transmission capacity inMHWSNs,an analytical framework for packet transmission using network coding at the MWR node in the network layer with opportunistic listening is performed by considering bi-directional network flow at the MWR node.Finally,the accuracy of the proposed multi-server multi-class queuing model is evaluated with and without network coding at the network layer by transmitting data packets.The results of the proposed analytical framework are validated and proved effective by comparing these analytical results to simulation results.

Value Function Mechanism in WSNs-Based Mango Plantation Monitoring System

Mango fruit is one of the main fruit commodities that contributes to Taiwan’s income.The implementation of technology is an alternative to increasing the quality and quantity of mango plantation product productivity.In this study,a Wireless Sensor Networks(“WSNs”)-based intelligent mango plantation monitoring system will be developed that implements deep reinforcement learning(DRL)technology in carrying out prediction tasks based on three classifications:“optimal,”“sub-optimal,”or“not-optimal”conditions based on three parameters including humidity,temperature,and soil moisture.The key idea is how to provide a precise decision-making mechanism in the real-time monitoring system.A value function-based will be employed to perform DRL model called deep Q-network(DQN)which contributes in optimizing the future reward and performing the precise decision recommendation to the agent and system behavior.The WSNs experiment result indicates the system’s accuracy by capturing the real-time environment parameters is 98.39%.Meanwhile,the results of comparative accuracy model experiments of the proposed DQN,individual Q-learning,uniform coverage(UC),and NaÏe Bayes classifier(NBC)are 97.60%,95.30%,96.50%,and 92.30%,respectively.From the results of the comparative experiment,it can be seen that the proposed DQN used in the study has themost optimal accuracy.Testing with 22 test scenarios for“optimal,”“sub-optimal,”and“not-optimal”conditions was carried out to ensure the system runs well in the real-world data.The accuracy percentage which is generated from the real-world data reaches 95.45%.Fromthe resultsof the cost analysis,the systemcanprovide a low-cost systemcomparedtothe conventional system.

Stochastic Ranking Improved Teaching-Learning and Adaptive Grasshopper Optimization Algorithm-Based Clustering Scheme for Augmenting Network Lifetime in WSNs

In Wireless Sensor Networks(WSNs),Clustering process is widely utilized for increasing the lifespan with sustained energy stability during data transmission.Several clustering protocols were devised for extending network lifetime,but most of them failed in handling the problem of fixed clustering,static rounds,and inadequate Cluster Head(CH)selection criteria which consumes more energy.In this paper,Stochastic Ranking Improved Teaching-Learning and Adaptive Grasshopper Optimization Algorithm(SRITL-AGOA)-based Clustering Scheme for energy stabilization and extending network lifespan.This SRITL-AGOA selected CH depending on the weightage of factors such as node mobility degree,neighbour's density distance to sink,single-hop or multihop communication and Residual Energy(RE)that directly influences the energy consumption of sensor nodes.In specific,Grasshopper Optimization Algorithm(GOA)is improved through tangent-based nonlinear strategy for enhancing the ability of global optimization.On the other hand,stochastic ranking and violation constraint handling strategies are embedded into Teaching-Learning-based Optimization Algorithm(TLOA)for improving its exploitation tendencies.Then,SR and VCH improved TLOA is embedded into the exploitation phase of AGOA for selecting better CH by maintaining better balance amid exploration and exploitation.Simulation results confirmed that the proposed SRITL-AGOA improved throughput by 21.86%,network stability by 18.94%,load balancing by 16.14%with minimized energy depletion by19.21%,compared to the competitive CH selection approaches.

基于WSNs的煤矿井下人员安全定位研究

针对现有煤矿井下人员安全定位方法存在的精度低、偏差大等问题,提出一种基于WSNs的井下人员定位方法。WSNs网络由大量随机布置的低成本无线传感器节点构成,在组网便捷性、功能性和稳定性等方面具有更大的优势。从结构设计方面来看,WSNs网络包括了普通传感器节点、汇聚节点、网关节点和后台上位机。其中普通节点负责采集其通信覆盖半径范围内相关数据信息,传递给汇聚节点。WSNs网络中的节点具有无线自组织的优势,其动态拓扑结构处于不断地变化之中且网络的稳定性较强。在基于WSNs网络传感器节点定位过程中,会存在一定偏差,为此,基于三角质心法可以实现井下人员的精准定位,提升煤矿井下人员作业过程的安全性。

Effective data transmission through energy-efficient clustering and Fuzzy-Based IDS routing approach in WSNs

Wireless sensor networks(WSN)gather information and sense information samples in a certain region and communicate these readings to a base station(BS).Energy efficiency is considered a major design issue in the WSNs,and can be addressed using clustering and routing techniques.Information is sent from the source to the BS via routing procedures.However,these routing protocols must ensure that packets are delivered securely,guaranteeing that neither adversaries nor unauthentic individuals have access to the sent information.Secure data transfer is intended to protect the data from illegal access,damage,or disruption.Thus,in the proposed model,secure data transmission is developed in an energy-effective manner.A low-energy adaptive clustering hierarchy(LEACH)is developed to efficiently transfer the data.For the intrusion detection systems(IDS),Fuzzy logic and artificial neural networks(ANNs)are proposed.Initially,the nodes were randomly placed in the network and initialized to gather information.To ensure fair energy dissipation between the nodes,LEACH randomly chooses cluster heads(CHs)and allocates this role to the various nodes based on a round-robin management mechanism.The intrusion-detection procedure was then utilized to determine whether intruders were present in the network.Within the WSN,a Fuzzy interference rule was utilized to distinguish the malicious nodes from legal nodes.Subsequently,an ANN was employed to distinguish the harmful nodes from suspicious nodes.The effectiveness of the proposed approach was validated using metrics that attained 97%accuracy,97%specificity,and 97%sensitivity of 95%.Thus,it was proved that the LEACH and Fuzzy-based IDS approaches are the best choices for securing data transmission in an energy-efficient manner.

基于改进行军蚁搜索优化器的异构WSNs覆盖增强策略

为了提高无线传感器网络(Wireless Sensor Networks,WSNs)随机部署后的覆盖效果,并且降低传感器节点在二次部署过程中的移动能耗,提出一种适用于感知半径异构的WSNs覆盖增强策略。该策略以行军蚁的种群规模作为节点部署方案,种群位置作为节点位置变量,建立了行军蚁优化器与WSNs覆盖问题的映射关系,并根据传感器节点的初始部署位置改进初始化行为,引入虚拟力导向作用改进攻击行为,基于巢穴位置改进蚁桥行为,从而在提高WSNs覆盖效果的基础上优化了传感器节点二次部署的移动能耗。仿真结果表明,相比于虚拟力算法、采样的异构WSNs覆盖优化算法与行军蚁优化器算法,所提算法的覆盖率较高,传感器节点二次部署过程中的移动距离最小。此外,当覆盖区域面积与节点规模变化时,所提算法在覆盖效果与移动能耗方面也具有较强的鲁棒性。

基于IPSO-BP神经网络的WSNs数据融合算法

针对无线传感器网络(WSNs)数据融合算法中反向传播(BP)神经网络存在对初值敏感、收敛速度慢、易陷入局部最优解等问题,提出基于改进粒子群优化BP(IPSO-BP)神经网络的WSNs数据融合算法。首先,用细菌觅食算法的趋化、迁徙算子对粒子群优化(PSO)算法进行改进;然后,用IPSO算法优化BP神经网络的权值和阈值,再引入到WSNs数据融合中,簇成员节点负责采集监测数据,在簇首节点通过优化后的BP神经网络对数据进行特征提取,并将融合结果发送至汇聚节点。仿真结果表明:IPSO-BP算法能有效提高融合精度和收敛速度,减少冗余数据传输,延长网络生命周期。

WSNs中基于占空比间隔优化的延迟约束路由算法

针对WSNs中现有路由算法存在的各种不足,提出了一种基于占空比间隔优化的延迟约束路由算法;具体来说,在提出的算法中,首先,将端到端延迟分布估计为占空比间隔和潜在转发器数量的函数,在给定的网络模型和参数下,其分布可以近似地估计;然后,选择满足延迟约束成功率要求的占空比间隔最大值,每个节点独立地调度其休眠和唤醒时间,发送端节点将数据包转发给潜在转发器中最先唤醒的节点,从而确保数据包以要求的概率即DCSR到达接收器,同时最大化占空比间隔;仿真实验结果表明,提出的路由算法不仅能够满足要求的DSCR,并在ETE延迟、数据包交付率和实际得到的DCSR方面都优于现有的先进算法。

基于改进RSSI测距的WSN机动目标跟踪算法

针对扩展卡尔曼滤波(EKF)在机动目标跟踪中传感器对机动目标进行测距时存在的噪声问题,提出了一种基于改进RSSI测距的WSN机动目标跟踪算法。首先,利用鱼鹰优化算法迭代寻优适合BP神经网络的权值和阈值;其次,将传感器的接收信号强度值作为神经网络的输入值,距离作为输出值对神经网络进行训练;最后,利用扩展卡尔曼滤波算法进行定位跟踪,利用匀速圆周运动模型(CM)进行滤波跟踪。使用EKF算法和RSSI算法与文中算法进行比较,以均方根误差为评价指标。经过仿真实验对比表明,所提算法相较于上述算法均方根误差分别降低了21%和56%。

基于全神经网络增强算法的WSNs故障预警与检测

针对现有WSNs故障检测算法存在的故障分类检测率低、耗时长、节点能耗控制差等问题,提出一种全神经网络增强故障预警与检测算法;全神经网络的神经元节点与临近层的节点连接,形成具有强大故障数据训练功能的深度网络结构,选择平滑性更好的sigmoid函数作为模型的激活函数,并基于感知机合理调节相邻两个隐含层之间的阈值权重,降低模型的训练损失;采用Adam优化算法抑制模型的梯度膨胀和梯度消失等异常情况,并消除训练中产生的数据冗余,以降低故障数据训练中产生的虚预警;实验结果显示:提出算法的总体故障检测率和不同类型故障的分类检测率都优于传统算法,此外全神经网络增强算法在节点故障检测耗时和能耗控制方面,也具有显著优势。

基于混合特征学习数学模型的WSNs入侵检测研究

随着WSNs入侵方式的多样化,现有检测算法的准确性会显著下降,为此提出了基于混合特征学习数学模型的WSNs入侵检测方法。检测中先基于嗅探器定时获取传感器节点运行参数,并利用熵权法选取无线传感器网络节点混合特征因子,包括能耗率、丢包率、报文发送频率、报文接收频率,再从获取传感器节点运行参数中获得四个特征因子对应的数值。利用BP神经网络构建入侵检测数学模型,以混合特征因子数值为输入,确定WSNs入侵类型,以实现对WSNs入侵行为的精确检测。结果表明:基于强化学习的入侵检测模型,基于双向循环生成对抗网络的入侵检测模型相比,所研究模型应用下,F1-measure数值更大,由此说明该模型入侵检测更全面,检测结果更准确,模型的整体性能更好。

基于改进镜面反射优化算法的WSNs覆盖优化

针对无线传感器网络(WSNs)节点部署存在覆盖盲区大和均匀分布性差等不足,提出一种改进镜面反射优化算法(MSRA)的WSNs覆盖优化方法。首先,采用种群策略将算法单一种群扩充为多种群,并引入Piecewice映射初始化种群,提高种群初始质量和搜索空间的遍历性;其次,融合了改进的Tent映射和莱维飞行方式对个体位置进行变异,提高算法跳出局部最优能力;然后,利用莱维飞行策略扰动最优个体位置,以平衡算法的全局探索与局部开发能力。仿真结果表明:相比镜面反射优化算法(SRA)和对比算法,所提算法寻优能力更优,有效地改善了WSNs节点分布的均匀性和覆盖盲区,提高了覆盖率。

无人机协助WSNs中的节能数据采集策略

在无线传感器网络(WSNs)中,无人机(UAV)已经成为一种有效的数据采集手段,但在采集过程中产生的大量能耗严重降低WSNs的寿命。针对WSNs中数据采集能量消耗大的问题,设计了一种基于传感器节点(SNs)唤醒调度和无人机轨迹设计的节能数据采集策略。基于该方案,构建了无人机与SNs能耗加权和最小化问题,该问题被描述为混合整数非线性规划(MINLP)问题,通常难以求解。针对该问题,提出一种基于路径离散化和连续凸逼近的联合优化算法,得到满足KKT条件的局部最优解。实验结果表明,所提出的方案能实现显著的网络节能,且能实现无人机能耗与SNs能耗之间的灵活权衡。

室内障碍环境下空气质量监测异构WSN部署

针对室内空气质量中污染性气体众多、浓度分布不均,单一传感器无法有效监测,而且室内障碍物会对传感器部署位置造成影响的问题,通过改进北方苍鹰优化算法(improved northern goshawk optimization,INGO)对障碍下异构传感器进行部署研究。首先,采用SPM混沌映射对种群进行初始化,以解决原始北方苍鹰算法初始化种群多样性不高、覆盖率低、冗余度高的问题;其次,使用非线性步长权重改进Lévy飞行策略,对种群位置进行更新;最后,融合柯西变异和反向学习,解决算法后期种群易陷入局部最优的问题。结果表明,改进的优化算法在无障碍和障碍环境下覆盖率分别达到了94.2%和93.0%,与其他学者在无障碍环境下提出的算法进行对比,覆盖率分别提高了0.8%,1.2%,2.8%,7.1%。INGO算法能够对室内障碍环境下的空气质量监测传感器进行最优部署,为室内空气质量监测等复杂环境异构传感器的部署问题提供科学依据。

考虑船舶动态位置的海底WSN节点能耗控制算法

由于海底环境并不具备连续稳定的电力供应,使得传感器节点通常依赖于有限的内部能量,而船舶在海底的动态位置会令节点密度布局变得更加复杂,从而导致WSN节点能量消耗不均衡。为此,提出考虑船舶动态位置的海底WSN节点能耗控制算法。建立海底WSN结构模型,利用多项式卡尔曼滤波器预测船舶轨迹;划分海底WSN簇结构,动态调整各簇的节点数量,控制海底WSN节点密度,建立船舶位置动态变化能耗模型,估算各簇节点在不同时间段的能耗需求,使其均衡消耗WSN节点能量,从而实现节点能耗控制。实验结果表明,本文算法应用后,有效平衡了节点能耗,保持连通性和覆盖性,提高海底WSN整体性能,稳定运行时间更长且失效节点增长较稳定。

A Layered Energy-Efficient Multi-Node Scheduling Mechanism for Large-Scale WSN

In recent years, target tracking has been considered one of the most important applications of wireless sensornetwork (WSN). Optimizing target tracking performance and prolonging network lifetime are two equally criticalobjectives in this scenario. The existing mechanisms still have weaknesses in balancing the two demands. Theproposed heuristic multi-node collaborative scheduling mechanism (HMNCS) comprises cluster head (CH)election, pre-selection, and task set selectionmechanisms, where the latter two kinds of selections forma two-layerselection mechanism. The CH election innovatively introduces the movement trend of the target and establishesa scoring mechanism to determine the optimal CH, which can delay the CH rotation and thus reduce energyconsumption. The pre-selection mechanism adaptively filters out suitable nodes as the candidate task set to applyfor tracking tasks, which can reduce the application consumption and the overhead of the following task setselection. Finally, the task node selection is mathematically transformed into an optimization problem and thegenetic algorithm is adopted to form a final task set in the task set selection mechanism. Simulation results showthat HMNCS outperforms other compared mechanisms in the tracking accuracy and the network lifetime.

基于自适应粒子群优化的WSNs非均匀分簇路由算法

针对无线传感器网络(WSNs)中存在的能量空洞问题,提出了一种基于自适应粒子群优化(PSO)的WSNs非均匀分簇路由(APSO-NUCR)算法。在簇首选举阶段,引入一个能量阈值从网络中筛选出候选簇首,候选簇首根据竞争半径构造规模大小不一的簇。引入PSO算法来确定簇首,建立基于节点能量和位置的适应度函数,根据适应度值来确定最终簇首。根据粒子当前适应度值计算惯性权重和学习因子,更新速度和位置,平衡算法的全局和局部搜索能力。在数据传输阶段,簇内采用单跳传输方式,簇间数据传输基于Prim最小生成树的最优多跳路径。仿真结果表明:APSO-NUCR算法在利用能量和均衡网络能耗方面有良好的性能,延长了网络寿命。

基于改进DDPG算法的WSN优化策略研究

DDPG算法是Actor-Critic和DQN算法的结合体,作为目前深度强化学习中最为经典的算法之一,被广泛应用于WSN。针对DDPG算法训练效率低、收敛速度慢、同步误差大等问题,提出一种基于加权信息熵的深度确定性策略梯度算法。该算法提前对训练数据进行权重分配,根据权重比例训练数据,并将结果通过神经网络集成。实验结果表明,相较于DQN和DDPG算法,WIE-DDPG算法的训练效率较高、收敛速度较快、同步误差较小。

WSN Mobile Target Tracking Based on Improved Snake-Extended Kalman Filtering Algorithm

A wireless sensor network mobile target tracking algorithm(ISO-EKF)based on improved snake optimization algorithm(ISO)is proposed to address the difficulty of estimating initial values when using extended Kalman filtering to solve the state of nonlinear mobile target tracking.First,the steps of extended Kalman filtering(EKF)are introduced.Second,the ISO is used to adjust the parameters of the EKF in real time to adapt to the current motion state of the mobile target.Finally,the effectiveness of the algorithm is demonstrated through filtering and tracking using the constant velocity circular motion model(CM).Under the specified conditions,the position and velocity mean square error curves are compared among the snake optimizer(SO)-EKF algorithm,EKF algorithm,and the proposed algorithm.The comparison shows that the proposed algorithm reduces the root mean square error of position by 52%and 41%compared to the SOEKF algorithm and EKF algorithm,respectively.

基于WSN+UWB的室内人员定位系统设计

随着社会发展,家长对幼儿安全越来越重视,幼儿园环境安全与否直接关系到儿童的健康及生命。为保障园区内幼儿状况及安全,文章提出了一种室内人员定位系统设计,该系统在满足基本定位需求的同时,采用了超宽带(Ultra Wide Band,UWB)技术,具有穿透性强、抗干扰和功耗低等优势,其性能表现已超过蓝牙和Wi-Fi,并以UWB技术作为主要技术依据,将无线传感网络(Wireless Sensor Network,WSN)技术与UWB技术相结合,设计了一款智能化的人员看护及定位系统,测试结果证明了该系统设计可满足园区内人员监测及定位警报的需求。