Modified Dwarf Mongoose Optimization Enabled Energy Aware Clustering Scheme for Cognitive Radio Wireless Sensor Networks

Cognitive radio wireless sensor networks(CRWSN)can be defined as a promising technology for developing bandwidth-limited applications.CRWSN is widely utilized by future Internet of Things(IoT)applications.Since a promising technology,Cognitive Radio(CR)can be modelled to alleviate the spectrum scarcity issue.Generally,CRWSN has cognitive radioenabled sensor nodes(SNs),which are energy limited.Hierarchical clusterrelated techniques for overall network management can be suitable for the scalability and stability of the network.This paper focuses on designing the Modified Dwarf Mongoose Optimization Enabled Energy Aware Clustering(MDMO-EAC)Scheme for CRWSN.The MDMO-EAC technique mainly intends to group the nodes into clusters in the CRWSN.Besides,theMDMOEAC algorithm is based on the dwarf mongoose optimization(DMO)algorithm design with oppositional-based learning(OBL)concept for the clustering process,showing the novelty of the work.In addition,the presented MDMO-EAC algorithm computed a multi-objective function for improved network efficiency.The presented model is validated using a comprehensive range of experiments,and the outcomes were scrutinized in varying measures.The comparison study stated the improvements of the MDMO-EAC method over other recent approaches.

Centralized Quasi-Static Channel Assignment for Multi-Radio Multi-Channel Wireless Mesh Networks

Employing multiple channels in wireless multihop networks is regarded as an effective approach to increas-ing network capacity. This paper presents a centralized quasi-static channel assignment for multi-radio multi-channel Wireless Mesh Networks (WMNs). The proposed channel assignment can efficiently utilize multiple channels with only 2 radios equipped on each mesh router. In the scheme, the network end-to-end traffics are first modeled by probing data at wireless access points, and then the traffic load between each pair of neighboring routers is further estimated using an interference-aware estimation algorithm. Having knowledge of the expected link load, the scheme assigns channels to each radio with the objective of mini-mizing network interference, which as a result greatly improves network capacity. The performance evalua-tion shows that the proposed scheme is highly responsive to varying traffic conditions, and the network per-formance under the channel assignment significantly outperforms the single-radio IEEE 802.11 network as well as the 2-radio WMN with static 2 channels.

Wireless Regional Area Networks and Cognitive Radio 2

IEEE has set up in October 2004 the IEEE802.22 Working Group-Wireless Regional Area Network (WRAN) Task Force to work out air interface standard based on Cognitive Radio (CR) technologies. The standard includes Physical Layer (PHY) and Media Access Control (MAC), utilizig the vacant spectrum bands already allocated to broadcast TV without interference.. The WRAN employs CR technologies to sense and estimate the television signals and use the technologies of dynamic spectrum management to find and then allocate vacant spectrums. The CR technologies are representing one of the major trends for future wireless communications. This article on WRANs and CR technologies will be divided into two issues. In this issue, WRANs and IEEE 802.22, CR technologies are introduced. And the second part in the next issue will analyze the applications of CR technologies.

Wireless Regional Area Networks and Cognitive Radio(1)

IEEE has set up in October 2004 the IEEE802.22 Working Group—Wireless Regional Area Network (WRAN) Task Force to work out air interface standard based on Cognitive Radio (CR) technologies. The standard includes Physical Layer (PHY) and Media Access Control (MAC),to use the already allocated fallow spectrums to broadcast TV in a non-interference way. The WRAN employs CR technologies to sense and estimate the television frequencies and use the technologies of dynamic spectrum management to find and then allocate idle spectrums. The CR technologies are representing one of the major trends for future wireless communications. This article on WRANs and CR technologies will be divided into two issues. In this issue,WRANs and IEEE 802.22,CR technologies are introduced. And the second part in the next issue will analyze the applications of CR technologies.

Parallel-Transmission: A New Usage of Multi-Radio Diversity in Wireless Mesh Network

To fully utilize the diversity of multi-radio, a new parallel transmission method for wireless mesh network is proposed. Compared with conventional packet transmission which follows “one flow on one radio”, it uses the radio diversity to transmit the packets on different radios simultaneously. Three components are presented to achieve parallel-transmission, which are control module, selection module and schedule module. A localized selecting algorithm selects the right radios based on the quality of wireless links. Two kinds of distributed scheduling algorithms are implemented to transmit packets on the selected radios. Finally, a parallel-adaptive routing metric is presented. Simulation results by NS2 show that this parallel-transmission scheme could enhance the average throughput of network by more than 10%.

Radio Coverage Mapping in Wireless Sensor Networks

Radio coverage directly affects the network connectivity, which is the foundational issue to ensure the normal operation of the network. Many efforts have been made to estimate the radio coverage of sensor nodes. The existing approaches (often RSSI measurement-based), however, suffer from heavy measurement cost and are not well suitable for the large-scale densely deployed WSNs. NRC-Map, a novel algorithm is put forward for sensor nodes radio coverage mapping. The algorithm is based on the RSSI values collected by the neighbor nodes. According to the spatial relationship, neighbor nodes are mapping to several overlapped sectors. By use of the least squares fitting method, a log-distance path loss model is established for each sector. Then, the max radius of each sector is computed according to the path loss model and the given signal attenuation threshold. Finally, all the sectors are overlapped to estimate the node radio coverage. Experimental results show that the method is simple and effectively improve the prediction accuracy of the sensor node radio coverage.

Cooperative Spectrum Sensing for Cognitive Radio-Wireless Sensors Network Based on OR Rule Decision to Enhance Energy Consumption in Greenhouses

Wireless sensors networks (WSNs) combined with cognitive radio have developed and solved the limited space of the frequency spectrum. In this paper, we propose different types of spectrums sensing and their own decisions depend on the probabilities that applied into fusion center, and how these probabilities’ techniques help to enhance the energy consumption of WSNs. In the same way, the importance of designing balanced distribution between the wireless sensors networks and their own sinks. This research also provides an overview of security issues in CR-WSN, especially in Spectrum Sensing Data Falsification (SSDF) attacks that enforces harmful effects on spectrum sensing and spectrum sharing. We adopt OR rule as four types of CRSN sensing protocolin greenhouses application by using Matlab and Netsim simulators. Our results show that the designing balanced wireless sensors and their sinks in greenhouses are very significant to decrease the energy, which is due to the traffic congestion in the sink range area. Furthermore, by applying OR rule has enhanced the energy consumption, and improved the sensors network lifetime compared to cognitive radio network.

An Energy-Efficient Duty-Cycled Wake-Up Radio Protocol for Avoiding Overhearing in Wireless Sensor Networks

Wake-up radio (WuR) system is often presented as the best candidate for replacing traditional duty cycled Medium Access Control (MAC) protocols in Wireless Sensor Networks (WSNs). The Double Radio (DoRa) protocol is a new MAC protocol for in-band WuR system with addressing capabilities. While the DoRa protocol improves the WSNs energy efficiency, it still suffers from an overhearing problem when the WuR system is very often requested. The WuR wastes a noticeable amount of energy when overhearing to wake-up demand intended to other nodes, but it is neither measured nor solved in other works. In this paper, an adaptive duty-cycled DoRa (DC-DoRa) is then proposed to solve the overhearing problem. The primary concept of the work is to enable the WuR functionality before the node is addressed and to disable the WuR after the node sent data. Extensive simulations under OMNeT++ using real input parameters are then performed to show the significant energy-savings through the two protocols and the nearly suppression of overhearing with DC-DoRa. In fact, the mean power consumption is three-order below using the DoRa protocol compared to traditional MAC protocols. While overhearing can represent up to 93% of the WuR energy consumption with the DoRa protocol, it is reduced to only 1% with the DC-DoRa protocol.

A Fault-Tolerant Cooperative Spectrum Sensing Algorithm over Cognitive Radio Network Based on Wireless Sensor Network

A serious threat to cognitive radio networks that sense the spectrum in a cooperative manner is the transmission of false spectrum sensing data by malicious sensor nodes. SNR fluctuations due to wireless channel effects complicate handling such attackers even further. This enforces the system to acquire authentication. Actually, the decision maker needs to determine the reliability or trustworthiness of the shared data. In this paper, the evaluation process is considered as an estimation dilemma on a set of evidences obtained through sensor nodes that are coordinated in an underlying wireless sensor network. Then, a likelihood-based computational trust evaluation algorithm is proposed to determine the trustworthiness of each sensor node's data. The proposed procedure just uses the information which is obtained from the sensor nodes without any presumptions about node’s reliability. Numerical results confirm the effectiveness of the algorithm in eliminating malicious nodes or faulty nodes which are not necessarily conscious attackers.

A New Distributed Localization Scheme for Wireless Sensor Networks

在无线传感器网络(WSN ) 的节点本地化是被对待一功能目标在纸从一个新奇观点追踪双。与在 WSN 的传统的追踪问题不同，使用静态的地点商品节点估计动人的目标，活动节点被用来帮助未知节点精确地发现他们的位置。一个新节点本地化计划虚拟烽火精力比率本地化(VB-ERL ) 和它为 WSN 的精炼被介绍。在计划，活动节点基于 Gauss-Markov 活动性模型搬到监视者地并且周期性地广播信息包。每个静态的未知节点在它的察觉到的范围收到虚拟烽火和精力，并且由发现一套超球面的交叉估计它的地点。模拟结果证明建议计划是有效的。

Managing Energy Consumption of Wireless Sensors Networks in Multiple Greenhouses

An extensive area implementation of fully observed greenhouses motivates on research, especially in remote greenhouses. However, implementation of wireless sensor networks (WSNs) is still needed for investigation. Cognitive radio sensor networks (CRSNs) took advantage of using the cognitive radio (CR) concept to which allowed wireless sensor networks to dynamically access into white space channels which is unused channels. In this paper, we adopted the Generalized Implicit-OR as CRSN sensing protocol to reduce the energy consumption and increase the network lifetime in multiple numbers of greenhouses. Our results showed that enhanced energy consumption and improved network lifetime compared to ordinary WSN.

无人机辅助传感器网络中吞吐量与节点能量优化方法

无人机凭借其高机动性可以对传感节点进行无线数据采集和无线供能,然而无线数据采集与无线供能是相互耦合的,如何对两者的资源分配和无人机飞行轨迹进行优化是无人机辅助无线供能传感器网络性能的关键。为此,提出了一种联合优化方案,通过交替优化节点接入、无人机三维飞行轨迹和能量数据传输时间分配,最大化最小节点效用。针对无线供能传感器网络模型中最大化最小节点效用问题提出了一个联合优化方案。由于该问题为非凸问题,提出了一个最大化最小节点效用算法(Maximized the Minimum Node Utility Algorithm,MMNUA),采用块坐标下降法将原始问题转化成4个子问题,并利用连续凸近似技术在每次迭代时依次优化4个子问题,使最大化最小节点效用逐渐收敛。与基础无人机方案相比,MMNUA使系统性能分别提升了14.1%、567.5%和177.0%,有效提高了无人机的工作效率,同时所提算法具有良好的收敛性和较小的复杂度。

多radio无线mesh网络跨层路由协议

与传统的无线多跳网络不同,多radio无线mesh网络的路由器是固定的,节点具有异构性。提出一种协作的异构多radio无线mesh系统路由设计模型,该路由协议模型按路由发现过程,分4个子模块,分别为半同步式邻居发现机制r、adio异构刻画的路由metric、分层的信息发布模型、满足业务需求的路由算法。该路由协议模型对多radio的异构性进行了刻画,采用分层协作方式共享网络拓扑信息。实验证明这种适应异构无线环境的跨层路由设计方案比传统方案更符合用户需求。

EasiTest:多Radio异构无线传感器网络测试平台

设计并实现了一种多Radio的异构无线传感器网络综合测试平台系统EasiTest,该平台采用了两种不同性能、功能的测试节点,可以支持大规模、异构传感器网络综合性能测试以及应用性研究.平台内采用了结构复杂、功能完备的多Radio的EZ271作为中高速测试节点,以及以 WiFi作为测试通道的EZ521作为中低速测试节点;系统提供传感/测试数据收集、数据管理、资源分配、服务器状态检查、节点状态检查与参数配置以及资源注册共享等功能模块,保障用户能够方便快捷地实现功能实验;通过友好的 Web访问页面,用户能够模拟真实的网络环境对多种类,如802.15.4,802.11协议等,以及多层次,如 MAC层、路由层、应用层等的网络协议研究成果进行灵活的综合实验验证,从而能够有效地提高无线传感器网络技术的研究效率.

基于智能反射面的无线携能认知网络鲁棒传输设计

针对智能反射面辅助的无线携能认知网络,提出了一种基于用户非完美信道状态信息的波束成形方案,提高网络的频谱和能量收集效率。在假设用户信道误差范数有界的条件下,建立了以信息接收用户最小可达速率最大化为目标函数,以满足信息接收用户和能量接收用户需求、主用户干扰阈值和基站最大发射功率为约束条件的优化问题。针对此非凸问题,提出利用三角不等式、交替方向乘子法和交替优化的迭代算法,以较低的计算复杂度求解得到基站的有源波束成形权矢量和智能反射面的无源波束成形矩阵。最后,仿真验证了所提方案相较于随机相位方案能够有效提高系统的性能,证明了在携能认知网络中引入智能反射面的可行性和有效性。

基于NS-3的光纤入室组网及空口调度仿真

目前的光纤接入无线网方案中,光网络与无线网络独立工作,缺乏协同工作机制,导致设备间相互干扰。通过引入中心化的决策控制机制,主设备基于从设备上报的信息进行集中决策控制,实现光纤与无线网络的协同工作。在NS-3平台添加XG-PON模块,对FTTR组网进行仿真,并设置主设备控制下的空口调度策略。仿真实现NS-3中XG-PON模块的上下行数据传输和上行带宽分配功能,并对FTTR网络下的多用户空口数据传输进行调度,在不同用户数量下,整网数据吞吐量分别获得0.64%~5.66%的提升,说明中心化决策机制具有有效的调度能力。

信能同传网络中基于能量的中继选择方法研究

针对中继节点能量受限的无线信能同传中继网络,中继节点可以从源节点的射频信号补充能量,并采用中继选择的方法,来延长中继网络的生命时间。首先,构建了中继网络性能约束条件下的能量受限中继节点处最小额外能量的优化目标,并将优化目标分为三个子问题进行求解,提出了通过动态调整功率分离因子来最优化中继节点处所需最小额外能量的方法;其次,通过仿真验证了所求出最优功率分离因子的有效性;然后,基于中继节点需要消耗的电池能量以及电池剩余能量,提出了两种能量意识的中继选择方法,分别是最小损失能量策略和最小损失能量比率策略;最后,通过仿真表明,最小损失能量比率策略优于最小损失能量策略,延长了网络生存周期,并提升了系统性能。

一个2.4 GHz集成的SP3T射频开关和低噪声放大器

基于90 nm SOI CMOS工艺实现的应用于无线局域网的2.4 GHz集成的单刀三掷(SP3T)射频开关和低噪声放大器.射频开关采用了一种低功耗的等效负压偏置方法,该方法能够在不使用负电压的前提下使关断状态晶体管获得等效的负压偏置,从而提高射频开关的线性度.低噪声放大器采用了负反馈技术和导数叠加技术提高线性度,利用导数叠加技术减小低噪声放大器的三阶非线性,进一步提高了负反馈低噪声放大器的线性度.低噪声放大器与射频开关集成,并带有Bypass衰减通路.测试结果表明,射频开关的发射支路实现了0.95 dB的插入损耗和34 dBm的输入1 dB压缩点,蓝牙支路具有1.68 dB的插入损耗和30 dBm的输入1 dB压缩点.在2 V供电下,接收支路在高增益模式下具有15.8 dB的增益,1.7 dB的噪声系数和7.6 dBm的输入三阶交调点,功耗28.6 mW,在Bypass模式下具有7.2 dB的插入损耗和22 dBm的输入三阶交调点.

基于WSN和RFID的矿井作业人员健康监测系统设计

针对煤矿井下工作场景恶劣复杂、人员健康及环境参数监控难度大、易造成安全事故等问题,采用物联网技术,设计了一种基于无线传感器网络(Wireless Sensor Networks,WSN)和射频识别(Radio Frequency Identification,RFID)的矿井作业人员健康监测系统。该系统利用WSN实时监控人体的心率、血氧及井下环境温湿度、气体浓度等数据;利用RFID技术定位井下作业人员;将所采集信息数据传输至服务器实时检测,实现安全预警并及时定位救援,从而远程监测作业人员健康。

低压配电网无线通信网络覆盖方案设计及性能评估

文章分析了低压配网特性及其对通信网络的需求,通过网关和终端设备的合理布局,提出了配网全覆盖、高可靠性通信的基于远距离无线电(Long Range Radio,LoRa)技术的无线通信网络覆盖方案。在此基础上,针对网络覆盖范围、通信稳定性、数据传输速率以及延迟等关键指标,采用仿真方法对所设计方案进行了性能评估。评估结果显示,提出方案的适应性较好,性能优越,为智能电网实现可靠通信提供了有效的解决方案,满足了低压配网通信的需求。