一种基于多权值优化的无线传感网分簇算法的研究

在无线传感网(WSN)中,网络的拓扑结构影响传感器节点的负载平衡,关系网络的容量与生存周期,而分簇结构是一种有效的拓扑控制方式。该文着眼于无线传感网络的拓扑结构,提出基于多权值的分簇算法MWBC(Multi-WeightBasedClustering),在初期通过节点间的信息交互,获得较多的局部网络信息,如:节点的度、当前能量值、发射功率、链路质量、相对位置等,在此基础上根据不同的网络应用背景作出不同的分簇决策,并预设簇的最大规模以利于接入协议的资源管理与分配。仿真结果表明,与具有代表性的分簇算法LEACH与HEED相比,在分簇的合理性上有较大的优势。     

无线传感网自适应能量驱动簇头轮换算法研究

分簇结构是大规模无线传感网(WSN)的一种有效的拓扑管理方法。在这种结构下,由于簇头(Cluster Head,CH)节点的能耗速率远高于簇成员节点(Cluster Member,CM),需要做簇头轮换以平衡网络能耗。该文分析了基于能量驱动的簇头轮换策略,并提供一种基于簇头节点实时负载来估计其启动轮换的能量阈值的自适应簇头轮换算法(Adaptive Cluster Rotation Algorithm,ACRA)。仿真结果表明,与现有算法如LEACH,EDAC等比较,ACRA算法最少化簇头轮换次数,延长了网络生存时间。     

Energy-efficiency clustering protocol in wireless sensor networks

The conventional clustering method has the unique potential to be the framework for power-conserving ad hoc networks. In this environment, studies on energy-efficient strategies such as sleeping mode and redirection have been reported, and recently some have even been adopted by some standards like Bluetooth and IEEE 802.11. However, consider wireless sensor networks. The devices employed are power-limited in nature, introducing the conventional clustering approach to the sensor networks provides a unique challenge due to the fact that cluster-heads, which are communication centers by default, tend to be heavily utilized and thus drained of their battery power rapidly. In this paper, we introduce a re-clustering strategy and a redirection scheme for cluster-based wireless sensor networks in order to address the power-conserving issues in such networks, while maintaining the merits of a clustering approach. Based on a practical energy model, simulation results show that the improved clustering method can obtain a longer lifetime when compared with the conventional clustering method.     

分簇路由的无线传感器网络通信模式与能量有效性研究

无线传感器网络中的节点以簇的方式进行路由时,簇成员可使用单跳或多跳通信模式将感知数据包发送至簇头。该文以簇内成员节点的最大能耗作为评价指标,研究单簇头情形下单跳和多跳的能量有效性,得出了通信模式的选择取决于通道衰减系数的结论。考虑到单纯的单跳或多跳模式会引起网络能耗不均衡,提出簇成员节点以一定概率在单跳和多跳间切换的混合通信模式,并给出了混合通信模式的工程实现方法。仿真结果验证了混合通信模式在能量有效性和能耗均衡分配方面的优势。     

Adaptive Storage Policy Switching for Wireless Sensor Networks

In wireless sensor networks, storage policies can be categorized into external storage, local storage and data centric storage. Each storage police has its suitable network environments. If a correct storage policy is chosen for a given network condition, unnecessary control messages can be significantly reduced. Then the network lifetime can be increased. In this paper, adaptive data storage (ADS) policy which can dynamically choose suitable storage policy for wireless sensor network according to the frequencies of user queries and events happening is proposed. Through collection and computation of user query and event rates, the proposed algorithm switches between local storage and data centric storage policies adaptively. Simulations are given to justify that the proposed adaptive storage policy indeed reduces the traffic in network and increases network lifetime.

An Approach to Increase the Lifetime of a Linear Array of Wireless Sensor Nodes

The nodes in a wireless sensor network are generally energy constrained. The lifetime of such a network is limited by the energy dissipated by individual nodes during signal processing and communication with other nodes. The issues of modeling a sensor network and assessment of its lifetime have received considerable attention in recent years. This paper provides an analytical framework for placing a number of nodes in a linear array such that each node dissipates the same energy per data gathering cycle. This approach ensures that all nodes run out of battery energy almost simultaneously. It is shown that the network lifetime almost doubles with the proposed scheme as compared to other reported schemes. However, in practice, the nodes are not expected to be placed as per this theoretical requirement. The issue of random placement of nodes has also been investigated to obtain the statistics of energy consumption of a node. The analytical results for random node placement are validated through simulation studies.

一种分层路由协议的改进和仿真分析﹡

在深入分析无线传感器网络路由协议设计目标的基础上,根据LEACH协议分层设计的思想,融入了负载平衡和簇内成树的思想,通过控制簇头之间的位置,使得簇的分布较为均匀,同时簇内节点根据节点的高度值形成一棵树,让节点采集到的数据沿着这棵树进行传输,使得簇内节点由单跳传输变成了多跳传输,很好的均衡了网络能耗.通过理论分析和仿真结果表明改进后的协议极大的延长了网络生命期, sink节点数据收集量也增加不少.     

基于离散多目标优化粒子群算法的多移动代理协作规划

无线传感器网络中多移动代理协作能快速高效地完成感知数据汇聚任务,但是随着移动代理访问数据源节点数的增加,移动代理携带的数据分组会逐渐增大,导致传感器节点能量负载不均衡,部分数据源节点能耗过快,网络生存期缩短。目前,针对该问题所设计的能耗均衡算法,多以降低多移动代理总能耗为目标,却未充分考虑部分数据源节点能量消耗过快对网络生存期造成的影响。提出离散多目标优化粒子群算法,以网络的总能耗和移动代理负载均衡作为适应度函数,在多移动代理协作路径规划中寻求近似最优解。通过仿真实验验证,所提出的多移动代理协作路径规划,在网络总能耗和网络生存期方面的性能优于同类其他算法。     

基于博弈的大规模无线传感器网络分簇算法

合理的分簇方式能够有效延长大规模无线传感器网络(LS-WSN)的寿命,从而降低其部署使用成本。当前很多WSN分簇的研究均假设节点均匀分布,这与实际应用中的大规模WSN有所差距。该文针对节点非均匀分布的大规模WSN,提出了一种分簇算法。该算法在基于蜂窝结构虚拟网格的位置分簇之后,引入博弈理论设计分簇调整流程,使网络达到各簇中节点数尽量均匀的分簇状态。理论分析和仿真结果证明,通过该方法进行分簇,可以有效均衡各个簇中的节点数,从而延长网络有效寿命。     

基于SMAC的无线传感网络组网方式

无线传感网络(WSN)具有十分广阔的应用前景,但以往的自组织组网方法仍有一些不足。本文首先对比分析以往的组网方法,根据无线传感网络的特点,提出了一种基于SMAC的自组织组网方法,最后与SMAC方法进行了实验对比。实验表明这种方法提高了网络资源的利用率,使网络链接的时间明显缩短,同时也减少了能耗。     

基于空间相关性的事件驱动无线传感器网络分簇算法

分簇算法是传感器网络中减少能量消耗的一种关键技术,它能够增强网络的扩展性和延长网络的生存时间。针对传感器节点数据的空间相关性,该文提出了一种新的基于空间相关性的事件驱动传感器网络分簇算法。算法根据用户要求的误差门限及结合节点数据的空间相关性马尔可夫模型,将事件感知区域划分成虚拟极坐标等价层。每个等价层选取层内当前剩余能量最大的节点作为簇头,网络通过移动代理收集簇头感知信息,该方法减少了传输数据量,有效节省了网络能量。     

基于动态半径的事件驱动型无线传感器网络分簇融合算法

事件驱动型无线传感器网络应用于突发事件监测,针对传统网络未考虑事件分布情况及成簇大小等问题,提出一种新的基于动态半径的分簇融合算法。综合考虑事件发生的严重程度及节点性能等因素确定簇头,并采用分级发射功率,根据成簇效果及网络平均能耗优化选择簇半径,实现在触发节点范围内的动态分簇,有效节约能耗、提高数据融合效率。仿真实验结果表明,与TEEN相比,该算法可显著延长无线传感器网络生命期。