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Wireless Networks - Wireless sensor networks are formed with very small sensor devices with limited energy and short transmission range. Sensors are randomly deployed in remote areas with harsh... 相似文献
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Wireless Networks - In wireless sensor networks, coverage and connectivity are the fundamental problems for monitoring the targets and guaranteed information dissemination to the far away base... 相似文献
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The major challenge in designing wireless sensor networks (WSNs) is the support of the functional, such as data latency, and the non-functional, such as data integrity, requirements while coping with the computation, energy and communication constraints. Careful node placement can be a very effective optimization means for achieving the desired design goals. In this paper, we report on the current state of the research on optimized node placement in WSNs. We highlight the issues, identify the various objectives and enumerate the different models and formulations. We categorize the placement strategies into static and dynamic depending on whether the optimization is performed at the time of deployment or while the network is operational, respectively. We further classify the published techniques based on the role that the node plays in the network and the primary performance objective considered. The paper also highlights open problems in this area of research. 相似文献
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Relay sensor placement in wireless sensor networks 总被引:4,自引:0,他引:4
This paper addresses the following relay sensor placement problem: given the set of duty sensors in the plane and the upper
bound of the transmission range, compute the minimum number of relay sensors such that the induced topology by all sensors
is globally connected. This problem is motivated by practically considering the tradeoff among performance, lifetime, and
cost when designing sensor networks. In our study, this problem is modelled by a NP-hard network optimization problem named
Steiner Minimum Tree with Minimum number of Steiner Points and bounded edge length (SMT-MSP). In this paper, we propose two approximate algorithms, and conduct detailed performance analysis. The first algorithm has
a performance ratio of 3 and the second has a performance ratio of 2.5.
Xiuzhen Cheng is an Assistant Professor in the Department of Computer Science at the George Washington University. She received her MS
and PhD degrees in Computer Science from the University of Minnesota - Twin Cities in 2000 and 2002, respectively. Her current
research interests include Wireless and Mobile Computing, Sensor Networks, Wireless Security, Statistical Pattern Recognition,
Approximation Algorithm Design and Analysis, and Computational Medicine. She is an editor for the International Journal on
Ad Hoc and Ubiquitous Computing and the International Journal of Sensor Networks. Dr. Cheng is a member of IEEE and ACM. She
received the National Science Foundation CAREER Award in 2004.
Ding-Zhu Du received his M.S. degree in 1982 from Institute of Applied Mathematics, Chinese Academy of Sciences, and his Ph.D. degree
in 1985 from the University of California at Santa Barbara. He worked at Mathematical Sciences Research Institutea, Berkeley
in 1985-86, at MIT in 1986-87, and at Princeton University in 1990-91. He was an associate-professor/professor at Department
of Computer Science and Engineering, University of Minnesota in 1991-2005, a professor at City University of Hong Kong in
1998-1999, a research professor at Institute of Applied Mathematics, Chinese Academy of Sciences in 1987-2002, and a Program
Director at National Science Foundation of USA in 2002-2005. Currently, he is a professor at Department of Computer Science,
University of Texas at Dallas and the Dean of Science at Xi’an Jiaotong University. His research interests include design
and analysis of algorithms for combinatorial optimization problems in communication networks and bioinformatics. He has published
more than 140 journal papers and 10 written books. He is the editor-in-chief of Journal of Combinatorial Optimization and
book series on Network Theory and Applications. He is also in editorial boards of more than 15 journals.
Lusheng Wang received his PhD degree from McMaster University in 1995. He is an associate professor at City University of Hong Kong. His
research interests include networks, algorithms and Bioinformatics. He is a member of IEEE and IEEE Computer Society.
Baogang Xu received his PhD degree from Shandong University in 1997. He is a professor at Nanjing Normal University. His research interests
include graph theory and algorithms on graphs. 相似文献
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Junhua Tang Sisi Dai Jianhua Li Shenghong Li 《International Journal of Communication Systems》2011,24(11):1418-1430
Directed diffusion (DD) is a promising data‐centric routing scheme for wireless sensor networks (WSNs). But the heavy flooding overhead involved in interest propagation causes scalability issues when DD is applied in large scale, interactive and dynamically changing sensor networks. To solve this problem, we propose a scalable version of DD called gossip‐based scalable directed diffusion (GSDD) in this paper. GSDD uses the same routing framework as DD but integrates gossiping in interest propagation and employs dynamic regional gossiping in path exploration phase to reduce the flooding overhead. Our analysis and simulation results demonstrate that GSDD is able to reduce the data delivery cost of DD by up to 25%; thus, significantly reduce energy consumption and prolong the lifetime of sensor nodes. Therefore, GSDD overcomes the scalability problem of DD and is suitable for large‐scale WSNs. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Hui Guo Rose Qingyang Hu Kejie Lu Yi Qian 《Wireless Communications and Mobile Computing》2014,14(9):922-936
In this paper, we address the energy‐efficient connectivity problem of a wireless sensor network (WSN) that consists of (1) static sensor nodes that have a short communication range and limited energy level, and (2) relay nodes that have a long communication range and unlimited power supply, and that can be added or relocated arbitrarily. For such a WSN, existing studies have been focused on the design of efficient approximation algorithms to minimize the number of relay nodes. By contrast, we propose a unified backbone construction framework that can be performed in a centralized manner with two objectives: (1) to minimize the number of nodes in the backbone and (2) to maximize the lifetime of the network. To solve such a challenging problem, we formulate three subproblems: (1) partial dominating set with energy threshold (PDSET); (2) partial dominating set with largest residual energy (PDSLE); and (3) minimum relay node placement (MRNP). For these three subproblems, we develop polynomial‐time algorithms. We also prove that our algorithm for PDSLE is optimal, and our algorithm for the PDSET and MRNP problems have small approximation ratios. Numerical results show that the proposed framework can significantly improve energy efficiency and reduce backbone size. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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In wireless sensor networks (WSN), which are composed of unreliable sensor nodes, preserving the connectivity is a serious problem and one of the most effective solutions of this problem is to deploy powerful relay nodes (RN). The location of the RN is an important parameter for the network performance. In this paper, we investigate relay node placement (RNP) problem on a weighted terrain structure to satisfy WSN connectivity. Contrary to the existing studies, instead of minimizing the number of RN, the main objective of weighted RNP is to minimize the total weight of the points on which RN are deployed. In order to solve the weighted RNP problem, a mathematical formulation is proposed to find the optimal solution. However, because of the NP-complete nature of the problem, a polynomial time heuristic algorithm is also developed. Performance results show that the proposed heuristic algorithm can find near-optimal solutions in a reasonable time bound. 相似文献
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To balancing energy consumption in wireless sensor networks, we proposed a fixed time interval node broadcasting scheme under variational acceleration straight-line movement model. Simulation results show that the approach proposed in this paper has a superior performance on energy consumption balance compared to uniform broadcasting methods. 相似文献
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针对MSP算法需要借助额外的外部扫描设备,不适合应用于对野外大规模部署的传感器网络进行定位这一缺点,提出了一种HG-MSP算法。该算法通过锚节点发出扫描信息,不需要额外的外部设备进行辅助定位,提高了算法的可用性。仿真实验表明,在去掉辅助设备的情况下,算法的定位精度并无明显下降。 相似文献
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基于矢量的无线传感器网络节点定位综合算法 总被引:2,自引:0,他引:2
基于DV-hop设计了一种节点的定位综合算法,并将其应用于移动节点.利用节点间估计距离和测量距离的差异构建位置校正矢量;通过改进的粒子群优化方法得到节点的校正步长;节点将其与位置校正矢量的乘积作为自身位置的校正值.通过仿真进行算法验证并分析了复杂度和有效性,结果证明该算法可以将DV-hop的定位误差下降75%,并且适用于稀疏网络. 相似文献
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无线传感器网络功率调整技术对于WSN节点的能量效率、生存时间、丢包率等性能均有显著影响,是其实用化的重要支撑技术。现提出了一种适用于无线传感器网络的自适应功率调整机制,只需要利用节点间的接收信号强度指示(RSSI)值,通过动态调整终端节点的功率值可以获得相对合适的发射功率,从而降低终端节点的能耗,可以适当延长节点的生存时间。实验结果证实了所提方法的有效性。 相似文献
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Large wireless sensor networks consisting of hundreds of devices are often used to conduct distinct monitoring tasks simultaneously. Furthermore, the significant events that can be detected by the network may be detected in many different parts of the network. As a consequence, these multiple tasks and diverse events may also cause resource contention and degradation of network quality of service. For instance, congestion created by regularly occurring events which do not need urgent forwarding to the monitoring centres may create delays for other events which need to be reported very rapidly. The Random Re-Routing (RRR) protocol for wireless sensor networks has therefore been proposed to adaptively prioritise the packets of certain urgent events above those of other less urgent events which may be of a more routine nature. In this paper we extend the RRR protocol to improve performance, and we use simulation experiments to illustrate heuristic algorithms for matching routing priorities to the requirements of the sensor network??s monitoring tasks. The approaches are based on selecting the protocol??s parameters prior to network deployment, and on using an acknowledgement mechanism for adapting the parameters during network operation. 相似文献
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Guangjie Han Deokjai Choi Wontaek Lim 《Wireless Communications and Mobile Computing》2009,9(8):1017-1027
The key problem of location service in indoor sensor networks is to quickly and precisely acquire the position information of mobile nodes. Due to resource limitation of the sensor nodes, some of the traditional positioning algorithms, such as two‐phase positioning (TPP) algorithm, are too complicated to be implemented and they cannot provide the real‐time localization of the mobile node. We analyze the localization error, which is produced when one tries to estimate the mobile node using trilateration method in the localization process. We draw the conclusion that the localization error is the least when three reference nodes form an equilateral triangle. Therefore, we improve the TPP algorithm and propose reference node selection algorithm based on trilateration (RNST), which can provide real‐time localization service for the mobile nodes. Our proposed algorithm is verified by the simulation experiment. Based on the analysis of the acquired data and comparison with that of the TPP algorithm, we conclude that our algorithm can meet real‐time localization requirement of the mobile nodes in an indoor environment, and make the localization error less than that of the traditional algorithm; therefore our proposed algorithm can effectively solve the real‐time localization problem of the mobile nodes in indoor sensor networks. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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In recent years there has been a growing interest in opportunistic routing as a way to increase the capacity of wireless networks by exploiting its broadcast nature. In contrast to traditional uni-path routing, in opportunistic routing the nodes overhearing neighbor’s transmissions can become candidates to forward the packets towards the destination.In this paper we address the question: What is the maximum performance that can be obtained using opportunistic routing? To answer this question we use an analytical model that allows to compute the optimal position of the nodes, such that the progress towards the destination is maximized. We use this model to compute bounds to the minimum expected number of transmissions that can be achieved in a network using opportunistic routing. 相似文献