共查询到17条相似文献,搜索用时 156 毫秒
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针对一种无线传感器网络节点的发射功率可变,其最大发射半径是最小能量发射半径r的k倍,即kr的传感器网络,研究节点最佳能量发射半径ir的设计问题。通过数学分析得到能量消耗公式,给出最优的能量发射级别k的计算方法。采用优化的发射功率相比采用固定功率的发射方法能够大幅度地提高网络寿命,对传感器网络的优化具有较好的指导作用。 相似文献
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基于均匀分簇的无线传感器网络寿命最大化理论分析 总被引:1,自引:0,他引:1
无线传感器网络路由协议的一个重要目标是均衡节点能量消耗并延长网络寿命.基于均匀分簇的无线传感器网络模型,对网络寿命最大化进行了理论分析.在此基础上,提出了一种改进的数据传输方式,有效地均衡了节点的能量消耗,并显著地延长了网络寿命.模拟实验表明,在网络半径一定时,通过合理地选取最优的簇半径,可以最大化网络寿命.改进数据传输方式后的最大网络寿命比改进前的提高了13%.最后,结合该领域当前研究现状,指出了基于分簇路由协议的最大网络寿命未来的研究重点. 相似文献
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无线传感器网络(WSNs)覆盖是WSNs的关键问题,它反映了网络对目标区域的探测能力,节点的感知距离的优化能够很好地解决WSNs区域覆盖要求的同时使得能量消耗最低.研究了基于节点感知距离参数调节的WSNs节能区域覆盖方案,建立了感知半径之和最小的数学模型,采用遗传算法求解该模型,得到一个最优解.仿真结果表明:与传统覆盖方案比较,所提方案在满足覆盖要求的同时有效地降低了网络能量消耗. 相似文献
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异构传感器网络能量空洞分析与避免研究 总被引:2,自引:0,他引:2
在无线传感器网络中,由于sink附近的节点承担远方节点数据的转发,故能量消耗较高,容易在sink附近形成能量空洞而使网络提前死亡.针对由初始能量较大节点充当簇头节点与初始能量较小的节点作为普通节点组成的异构分簇无线传感器网络,提出了不等簇半径工作能量空洞避免策略.策略的核心是让近sink的簇半径较小,而远sink的簇半径较大,这样,近sink部署的初始能量较大的簇头节点较多,因而能够减弱能量空洞的影响,以达到能量消耗均衡的目的.将能量空洞避免问题转化为在保证网络寿命满足应用需求约束前提下如何使部署的节点最小的优化问题,并详细给出了不等簇半径的取值与优化方法.理论分析与实验结果表明,所提出的策略对网络寿命与性能有较大的改善,对于异构传感器网络建设有较好的指导意义. 相似文献
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多sink节点数量和位置的合理部署能有效延长无线传感器网络寿命、控制网络成本。基于随机分布无线传感器网络结构,建立了网络寿命模型和成本模型,并采用网络寿命成本比(RLC)推导出使网络寿命和网络成本综合最优的sink节点数目的表达式。同时,还提出RDF算法可以在给定sink节点数目的情况下,快速有效地确定sink节点位置。通过理论分析和仿真验证,证明采用本文提出的部署策略能有效延长网络寿命,同时降低网络部署成本。 相似文献
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Heterogeneity of node energy is a common phenomenon in wireless sensor networks. In such node energy heterogeneous sensor network, how to balance the energy consumption is the key problem on extending the lifetime of the sensor network system. An energy-efficient self-organisation algorithm with heterogeneous connectivity based on energy-awareness is proposed. Each sensor node in the network adjusts its own transmission radius based on the local energy information during the constructing and operating phase. Thus heterogeneous network topology, in which the nodes can choose different transmission radius, is formed. In contrast to the homogeneous network model, in which the node carries the same radius, simulation and analysis are conducted to explore the topology characteristics and robustness with different node energy distribution. The degree distribution shows the scale-free property in the heterogeneous model. The proposed network model enjoys higher efficiency of transmitting data, less clustering, higher robustness under node random failures and longer network lifetime than those in the homogeneous ones. 相似文献
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引入一种新的抗毁性指标——自然连通度,建立了考虑能耗的移动Ad hoc网络拓扑结构抗毁性综合测度模型,在此基础上确定了基于网络拓扑结构抗毁性的最优发射半径。实验分析表明,该测度模型能有效刻画移动Ad hoc网络拓扑结构的抗毁性,具有最优发射半径的网络拓扑结构能较好权衡网络结构抗毁性和网络生命期。 相似文献
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We consider the problem of optimal energy allocation and lifetime maximization in heterogeneous wireless sensor networks. We construct a probabilistic model for heterogeneous wireless sensor networks where sensors can have different sensing range, different transmission range, different energy consumption for data sensing, and different energy consumption for data transmission, and the stream of data sensed and transmitted from a sensor and the stream of data relayed by a sensor to a base station are all treated as Poisson streams. We derive the probability distribution and the expectation of the number of data transmissions during the lifetime of each sensor and the probability distribution and the expectation of the lifetime of each sensor. In all these analysis, energy consumption of data sensing and data transmission and data relay are all taken into consideration. We develop an algorithm to find an optimal initial energy allocation to the sensors such that the network lifetime in the sense of the identical expected sensor lifetime is maximized. We show how to deal with a large amount of energy budget that may cause excessive computational time by developing accurate closed form approximate expressions of sensor lifetime and network lifetime and optimal initial energy allocation. We derive the expected number of working sensors at any time. Based on such results, we can find the latest time such that the expected number of sensors that are still functioning up to that time is above certain threshold. 相似文献
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基于蚁群优化解决传感器网络中的能量洞问题 总被引:10,自引:0,他引:10
基于多跳的无线传感器网络,越靠近sink的传感器节点因需要转发更多的数据,其能量消耗就越快,从而在sink周围形成了一种称为“能量洞”的现象.“能量洞”问题会导致整个网络由于内部节点能量过早耗尽而结束寿命,同时,网络中离sink较远的节点仍有大量能量剩余.研究“能量洞”现象,基于改进的分级环模型,总结出调节各环内节点的数据传输距离是实现网络节能的有效方法.证明搜索各区域最优的传输距离是一个多目标优化问题,即是NP难问题.从而提出一种基于蚁群优化的分布式算法,各区域根据其节点分布情况自适应地探索近似最优的传输距离,延长网络寿命.模拟实验结果表明,该算法在较短的时间内能够收敛到合理的解,并且得到的网络寿命接近于理想情况下的最优时间,与现有的类似算法相比,该算法提供了更长的网络寿命,并能适用于非均匀节点分布情况. 相似文献
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Devesh K. Jha Thomas A. Wettergren Kushal Mukherjee 《International journal of control》2013,86(9):1775-1788
In general, battery-powered sensors in a sensor network are operable as long as they can communicate sensed data to a processing node. In this context, a sensor network has two competing objectives: (1) maximisation of the network performance with respect to the probability of successful search for a specified upper bound on the probability of false alarms, and (2) maximisation of the network’s operable life. As both sensing and communication of data consume battery energy at the sensing nodes of the sensor network, judicious use of sensing power and communication power is needed to improve the lifetime of the sensor network. This paper presents an adaptive energy management policy that will optimally allocate the available energy between sensing and communication at each sensing node to maximise the network performance subject to specified constraints. Under the assumptions of fixed total energy allocation for a sensor network operating for a specified time period, the problem is reduced to synthesis of an optimal network topology that maximises the probability of successful search (of a target) over a surveillance region. In a two-stage optimisation, a genetic algorithm-based meta-heuristic search is first used to efficiently explore the global design space, and then a local pattern search algorithm is used for convergence to an optimal solution. The results of performance optimisation are generated on a simulation test bed to validate the proposed concept. Adaptation to energy variations across the network is shown to be manifested as a change in the optimal network topology by using sensing and communication models for underwater environment. The approximate Pareto-optimal surface is obtained as a trade-off between network lifetime and probability of successful search over the surveillance region. 相似文献