基于贝叶斯网络的WSNs链路质量评估机制研究

在无线传感器网络(WSNs)应用中,链路质量的有效评估是保障数据可靠传输和上层网络协议性能的基础性问题.针对现有无线链路质量评估研究中,链路质量等级划分仍无统一标准和模型缺乏环境自适应性问题,提出了一种基于贝叶斯网络的链路质量评估机制.从链路质量多属性角度出发,采用贴近度分析法对链路质量等级进行划分,利用贝叶斯网络对链路质量进行不确定性推理与评估建模.通过多应用场景的训练与测试,最后实际测试表明:基于贝叶斯网络的评估模型在不同应用环境具有较高准确率和泛化能力,体现了良好的自适应性.     

TCP Veno协议的性能分析与评价

TCP Veno协议综合了TCP Reno和TCP Vegas的特点,通过对慢启动,拥塞避免和快速恢复算法的改进,使TCP协议在无线网络环境下性能有了较大的改善.为求更加客观和直观的展示Veno的性能,在NS-2环境下对TCP Veno和几种不同版本的TCP协议进行了对比分析.结果显示,TCP Veno协议在无线环境中表现优良,尤其是链路差错率较高的情况下,TCPVeno的性能较其它版本的TCP协议为好,改善了无线环境中因随机丢包而引起的网络性能下降情况.     

一种基于TopDisc的WSNs拓扑控制算法

针对无线传感器网络（WSNs）中无线信号动态波动变化时引起网络链路不稳定和覆盖范围变小的问题,提出了一种基于TopDisc的WSNs拓扑控制算法.该算法通过引入拓扑控制参数控制网络拓扑优化以适应无线信号变化,给出了拓扑创建过程,对算法进行了仿真实验.仿真结果表明：改进的拓扑控制算法能够提升WSNs对复杂无线电环境的适应能力,提高了资源利用率和链路可靠性.     

基于LEACH和PEGASIS的节能可靠路由协议研究

由于无线传感器网络节点的能量是有限的,因此设计能量有效的路由协议是非常重要的。LEACH和PEGASIS是无线传感器网络中典型的层次路由协议。文中在两者的基础上提出了一种改进的节能可靠路由协议,在簇形成过程中低能量簇首节点可以通过寻找替代簇首,均衡负载,避免过早死亡;在簇首之间形成一条链路主干路由,进行数据融合以及多跳传输,并针对链路易断的缺点提出一种可靠传输机制。理论分析及仿真结果表明。新提出的路由协议比LEACH更能均衡并减少能量消耗,延长了网络的生命周期。     

井下无线传感器网络路由协议的研究

为了研究煤矿监测无线传感器网络的特殊环境,对NS2网络仿真场景进行了扩充,在NS2中加入障碍物构造出井下掘进工作面的场景.通过分析当前经典的无线传感器网络协议DSDV、DSR、AODV以及GPSR,使其运行在井下特殊的场景中.无线传感器网络由能量受限的节点组成,能量问题在井下尤为重要,在NS2中引入能量模型对其协议进行对比.按照包成功投递端到端的平均延时、包成功投递率和能量消耗这三个指标对四个路由协议进行了性能仿真评估,仿真结果表明基于地理位置信息的GPSR协议在井下表现出较好的特点、鲁棒性和节能效应,因此当网络结构变化频繁,要求较高的分组投递率时可选择GPSR协议.     

面向农业应用的WSNs路由恢复算法

无线传感器网络(WSNs)作为现代重要的信息技术之一,在农业生产领域具有广阔的前景.以灌溉系统为具体应用场景,提出一种基于WSNs的农业应用设计方案,设计方案包括灌溉系统的总体设计、硬件设计和软件设计.还针对因节点故障导致的路由链路中断问题设计了WSNs的路由恢复算法,并对这种路由恢复算法进行了仿真.仿真表明:这种路由恢复算法传输的包数量比动态源路由(DSR)协议更少,可以有效降低节点的能耗.     

基于模糊认知图的智能配电网WSNs实时性与可靠性优化研究

为了降低智能配电网事故,提高智能配电网无线传感器网络（WSNs）数据通信的可靠性与实时性,探索了一种基于模糊认知图的智能配电网WSNs数据通信建模与控制的方法。首先,定性分析影响智能配电网WSNs数据传输的性能指标的主要因素,构建模糊认知图模型,根据网络环境的变化利用数学方法表达网络节点各概念顶点之间的因果关系;然后,再利用模糊认知图的方法进行推理,获得动态决策路由路径和调整网络参数的控制变量值;最后,对本文方法进行仿真实验,对数据传输性能进行了测试分析。实验结果表明所提出的方法可为智能配电网WSNs数据传输提供良好的QoS（服务质量）。     

基于Ad-Hoc的交通隧道无线传感器网络视频传输研究

在搭建交通隧道无线传感器网络（ WSNs）模型的基础上,分析交通隧道无线信号的传输特性。运用经典的Ad-Hoc路由协议构造仿真场景,从描述图像质量的平均峰值信噪比（ PSNR）值和描述网络质量的平均时延两个方面分析交通隧道中无线传感器网络传输视频图像的性能。研究表明：使用基于Ad-Hoc路由协议的传感器网络传输视频图像可以满足交通隧道监控的要求,按需距离矢量路由（ AODV）协议传输的视频图像质量优于目的序列距离矢量路由（ DSDV）协议。     

分簇无线传感器网络多Sink多信道传输方案

针对无线传感器网络(WSNs)在大规模网络应用时出现的问题,通过对 Siphon 协议的研究,提出一个基于分簇网络结构的多 Sink 多信道传输方案,并采用多信道的方法解决簇间传输干扰问题,在保证节点有效利用能量的同时提高 WSNs 的数据传输性能.介绍和分析"漏斗效应"和 Siphon 协议,对平面网络结构和分簇网络...     

无线传感器网络跨层参数模型设计

通过对现有多种无线传感器网络（WSNs）跨层协议的分析和研究,提出一种新型的跨层参数参考模型。该模型给出WSNs中网络层、数据链路层以及物理层等各层次之间相互影响的参数。在此基础上,分析该模型中网络各层次参数之间对网络性能的影响。最后通过对多个参数进行仿真实验,得出各参数对网络性能的影响情况,并作出理论分析,从而验证该模型的有效性。     

无线传感器网络MAC协议的设计研究

媒体访问控制(MAC)协议是无线传感器网络协议的重要组成部分,它的性能好坏直接关系到无线信道的利用效率和整个网络的性能。介绍了无线传感器网络MAC协议设计的主要问题,根据设计指标的不同对无线传感器网络MAC协议进行了分类,并在此基础上,分析研究了几种典型的无线传感器网络MAC协议采用的机制和方法。     

An improved transport layer protocol for wireless sensor networks

Wireless sensor networks (WSNs) are a kind of communication networks having independent sensor nodes that form multi-hop ad hoc network to transfer data. In the past few years, various transport control protocols in wireless sensor networks (WSNs) have been developed and proposed in the literature. In this paper, we have analyzed pump slowly, fetch quickly (PSFQ) protocol and presented an improved transport layer protocol for wireless sensor networks. The improved protocol has been analyzed based on various factors such as average latency and average error tolerance and it is found that the proposed protocol is better than PSFQ in terms of these factors.     

A Class of Cross‐Layer Optimization Design for Congestion and Energy Efficiency with Compressed Sensing in Wireless Sensing Networks

In wireless sensor networks (WSNs), the congestion problem not only causes packet loss, but also leads to an increase in delays and energy consumption. The actual performance of wireless sensor networks (WSNs) can be severely influenced by the quality of the communication channel and the bit in transmission. In this paper, the distributed protocols, which attain global optimum control for signals by the compressed sensing technique and achieve fair channel allocation by the scheduling algorithm, are proposed for WSNs. We take into account the congestion problem by robust optimization with congestion ratio for two classic aspects in energy limited WSNs: minimum transmission rate and maximum transmitted information. To achieve the goal, three protocols are developed. In the first protocol, the desired control input is designed based on the compressed sensing technique. A minimal bit of signal is provided to reduce the transmission flow for the congestion model. The second protocol is resource allocation. The resources can be allocated increasingly to the channel in order to avoid more severe congestion. This can also avoid conservative reduction of resource allocation for eliminating congestion. Channel selection abides by the fair resource allocation principle. The above protocols separately are implemented through a congestion ratio at network layer, transport layer, and MAC layer. Simulation results demonstrate that the proposed algorithm effectively relieves congestion, and achieves higher throughput and lower energy consumption.     

Network resource management mechanisms in SDN enabled WSNs: A comprehensive review

Wireless technologies usually have very limited computing, memory, and battery power that require the optimal management of network resources to increase network performance. The optimization of these network resources provides an efficient network topology, traffic control, routing, and data aggregation. This study presents a qualitative and quantitative investigation to evaluate the efficient network resource management mechanisms for software defined wireless sensor networks (SDN-enabled WSNs) from the beginning of network design to reliable data delivery. In this paper, a taxonomy of network resource management research studies is proposed. A detailed analysis of SDN-enabled WSNs architecture, SDN controllers, topology discovery, routing approaches, flow rules installation, and data aggregation is also discussed. Furthermore, the comparative analysis of resource provisioning methods along with various simulation tools is presented. Moreover, this review outlines open research challenges and prospective future directions for network resource management in SDN-enabled WSNs.     

SR-MAC: A Low Latency MAC Protocol for Multi-Packet Transmissions in Wireless Sensor Networks

Event detection is one of the major applications of wireless sensor networks (WSNs). Most of existing medium access control (MAC) protocols are mainly optimized for the situation under which an event only generates one packet on a single sensor node. When an event generates multiple packets on a single node, the performance of these MAC protocols degrades rapidly. In this paper, we present a new synchronous duty-cycle MAC protocol called SR-MAC for the event detection applications in which multiple packets are generated on a single node. SR-MAC introduces a new scheduling mechanism that reserves few time slots during the SLEEP period for the nodes to transmit multiple packets. By this approach, SR-MAC can schedule multiple packets generated by an event on a single node to be forwarded over multiple hops in one operational cycle without collision. We use event delivery latency (EDL) and event delivery ratio (EDR) to measure the event detection capability of the SR-MAC protocol. Through detailed ns-2 simulation, the results show that SR-MAC can achieve lower EDL, higher EDR and higher network throughput with guaranteed energy efficiency compared with R-MAC, DW-MAC and PR-MAC.     

三维无线传感器网络贪婪地理路由协议

针对已有的三维无线传感器网络路由协议均将三维问题转换到二维平面上解决,没有充分利用三维空间的特点,提出了一种基于地理信息的三维无线传感器网络贪婪地理路由(GGR)协议。该协议在通常状况下采用贪婪转发算法,针对基于地理信息的贪婪算法中易出现的路由空洞问题,给出一种三维滚动球边界遍历算法。实验结果表明:该协议具有较高的路由成功率,路由跳数也得到优化,尤其是在节点密度较低的情况下体现出较强的优势。     

Editorial

Wireless sensor network(WSN)is characterized by the dense deployment of sensor nodes that continuously observe physical phenomenon.The main advantages of WSN include its low cost,rapid deployment,self-organization,and fault tolerance.WSN has received tremendous interests of various research communities,and significant progresses have been made in various aspects including sensor platform development,wireless communication and networking,signal and information processing,as well as network performance eva...     

无线传感器网络能量多路径路由研究

研究了无线传感器分层网络模型及能量多路径路由机制．为解决现有协议的缺陷，提出了改进型能量多路径路由协议(IMP-EA)，建立了路由算法．以网络寿命和丢包率作为评价指标，对改进型能量多路径路由协议和其它3种路由协议进行了仿真实验．仿真结果表明，改进后的协议有效地延长了网络的生存时间，提高了数据转发效率．     

基于路径质量的无线传感网路由协议

基于跳数的无线传感器网络路由协议因实现简单、延迟少和易维护等优点,一直以来受到广泛关注。在分析现有基于跳数的路由协议的基础上,对最小跳数路由算法的选路标准进行了改进,提出了一种基于路径质量的无线传感网路由协议,采用跳数、综合链路质量和节点能量作为路径质量的度量指标。使用OMNET++网络仿真软件进行了仿真实验,实验结果表明：改进后的路由协议有效地提高了网络分组的投递率,降低了网络的能耗。