传感器网络的节点调度与休眠算法研究
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摘要
在构建无线传感器网络时,网络覆盖是无线传感器网络的基本问题之一。无线传感器网络的覆盖控制问题,可以看作是在传感器网络节点能量、无线网络通信带宽、网络计算处理能力等资源普遍受限情况下,通过网络传感器节点放置以及路由选择等手段,最终使无线传感器网络的各种资源得到优化分配,进而使感知、监视、传感、通信等各种服务质量得到改善。覆盖算法设计的基本目标是能够在满足一定冗余度的前提下实现更大区域的探测,从而获得更多的被探测目标的信息,同时由于节点的能量是的限制,还必须考虑算法的复杂度和有效性,平衡总体能量消耗和单个节点能量消耗之间的关系,以及节点的减少和添加对整个无线传感器网路节点覆盖的影响等等。
本文首先介绍了无线传感器网络覆盖问题的研究现状和相关问题,并简要介绍了传感器网络研究中涉及较多的Delaunay三角划分图的相关背景知识,其中重点介绍了局部Delaunay三角划分图的构造方法,这是本文算法的理论基础。接着介绍了覆盖问题中的节点调度算法,并对现有算法进行了比较和分析,在此基础上对虚拟力算法进行了改进,引入了两种新的虚拟力形式:随机扰力和临界外力,用于控制传感器节点覆盖网络的扩散和收缩。实验结果表明,改进的算法在各项主要性能指标上均优于现有算法。然后本文分析了传感器网络中的冗余节点休眠问题,提出了一种基于局部Delaunay三角划分图的分布式冗余节点判别方法和节点多轮选举休眠机制。实验结果表明,该方法能够有效的判别网络中的冗余节点;同时,通过多轮选举机制,可以在保证原有覆盖的情况下休眠部分冗余节点,减少网络的能量消耗。
最后是全文总结和对无线传感器网络中覆盖问题的进一步研究方向进行了探讨和展望。
During constructing the wireless sensor networks (WSN), network coverage is one of the basic items. The problem of coverage control can be treated as making the resource in WSN get optimization assignment so as the detecting, sense, monitor and communication in QOS achieve improvement, using deployment of nodes, routing selection or other methods in constrain of the nodes’energy, channel bandwidth and network processing capacity. The primary destination of coverage algorithm design is to sense larger area and get more information of target with certain redundancy. At the same time, power of nodes is limited so that the complexity and validity of algorithm should be considered. In addition, design of coverage algorithm should consider the static and dynamic property of the whole network, including validity and connectivity of network and reducing of nodes.
This paper introduces the present reach on coverage algorithm of WSN and same related work at the beginning, such as Delaunay tessellation which widely used in WSN. Conformation of local Delaunay tessellation is introduced as important because it is the fundament of the algorithm.
The third part of the paper introduces the node-scheduling in WSN and some issued methods are compared and analyzed. As fundament of this, it improves the potential field algorithm and introduces twos kinds of virtual force: random disturbance force and boundary force, which used to control the diffusion and contraction of network. The experimental result shows that new virtual force can eliminate the center confusion which cause by issued algorithm. Nodes cover the destination evenly and energy consumption is less than other main node-scheduling methods.
In the following, this paper introduces the dormancy problem of redundant nodes and proposes a distributed redundant node distinguish algorithm and rotated voting to shutdown algorithm based on local Delaunay tessellation. The experiment result shows that it can determine redundant nodes in the network effectively. At the same time, the rotated voting to shutdown algorithm can shutdown the redundant nodes without reducing the initial coverage area and reduce power consumption.
Finally, it’s the overall summarization of the paper and research expectation of coverage algorithm in wireless sensor networks.
本文首先介绍了无线传感器网络覆盖问题的研究现状和相关问题,并简要介绍了传感器网络研究中涉及较多的Delaunay三角划分图的相关背景知识,其中重点介绍了局部Delaunay三角划分图的构造方法,这是本文算法的理论基础。接着介绍了覆盖问题中的节点调度算法,并对现有算法进行了比较和分析,在此基础上对虚拟力算法进行了改进,引入了两种新的虚拟力形式:随机扰力和临界外力,用于控制传感器节点覆盖网络的扩散和收缩。实验结果表明,改进的算法在各项主要性能指标上均优于现有算法。然后本文分析了传感器网络中的冗余节点休眠问题,提出了一种基于局部Delaunay三角划分图的分布式冗余节点判别方法和节点多轮选举休眠机制。实验结果表明,该方法能够有效的判别网络中的冗余节点;同时,通过多轮选举机制,可以在保证原有覆盖的情况下休眠部分冗余节点,减少网络的能量消耗。
最后是全文总结和对无线传感器网络中覆盖问题的进一步研究方向进行了探讨和展望。
During constructing the wireless sensor networks (WSN), network coverage is one of the basic items. The problem of coverage control can be treated as making the resource in WSN get optimization assignment so as the detecting, sense, monitor and communication in QOS achieve improvement, using deployment of nodes, routing selection or other methods in constrain of the nodes’energy, channel bandwidth and network processing capacity. The primary destination of coverage algorithm design is to sense larger area and get more information of target with certain redundancy. At the same time, power of nodes is limited so that the complexity and validity of algorithm should be considered. In addition, design of coverage algorithm should consider the static and dynamic property of the whole network, including validity and connectivity of network and reducing of nodes.
This paper introduces the present reach on coverage algorithm of WSN and same related work at the beginning, such as Delaunay tessellation which widely used in WSN. Conformation of local Delaunay tessellation is introduced as important because it is the fundament of the algorithm.
The third part of the paper introduces the node-scheduling in WSN and some issued methods are compared and analyzed. As fundament of this, it improves the potential field algorithm and introduces twos kinds of virtual force: random disturbance force and boundary force, which used to control the diffusion and contraction of network. The experimental result shows that new virtual force can eliminate the center confusion which cause by issued algorithm. Nodes cover the destination evenly and energy consumption is less than other main node-scheduling methods.
In the following, this paper introduces the dormancy problem of redundant nodes and proposes a distributed redundant node distinguish algorithm and rotated voting to shutdown algorithm based on local Delaunay tessellation. The experiment result shows that it can determine redundant nodes in the network effectively. At the same time, the rotated voting to shutdown algorithm can shutdown the redundant nodes without reducing the initial coverage area and reduce power consumption.
Finally, it’s the overall summarization of the paper and research expectation of coverage algorithm in wireless sensor networks.
引文
[1]颜振亚,郑宝玉.无线传感器网络.计算机工程与应用, 2005(15) 20-23
[2]芦东昕,徐文龙,王利存.无线传感器网络.工业控制计算机, 2005年第18卷第4期24-25
[3]任丰原,黄海宁,林闯.无线传感器网络.软件学报, Vol.14 No.7
[4]盛超华,陈章龙.无线传感器网络及应用.微型电脑应用, 2005年第21卷第6期10-13
[5]韩立锋.无线传感器网络技术.网络通信, 2005年第4期15-17
[6]滑楠,史浩山,吴健.无线传感器网络主动QoS机制研究.计算机工程与应用, 2005 Vol.14 120-137
[7]马祖长,孙怡宁,梅涛.无线传感器网络综述.通信学报, 2004年4月第25卷第4期114-124
[8]李国华,沈树群,自组织无线传感器网络的研究.数据通信, 2004年第4期1-4
[9]刘刚,周兴社,谷建华,李志刚.自组织自适应无线传感器网络理论研究.计算机应用研究, 2005年第5期30-33
[10] O’Rourke J.Art gallery theorem and algorithms[M].New York: Oxford University Press, l997
[11] Meguerdichian S, Koushanfar F, Potkonjak M, et al. Coverage problems in wireless Ad-hoc sensor networks [J]. INFOCOM’01, 2006, (3):1380-1387
[12] Chakrabarty K, lyengar S, Qi H, et al. Grid coverage for surveillance and target location in distributed sensor networks [J]. IEEE Trans. on Computers, 2002, 51(12): l448-l453
[13] Bulusu N, Heidemann J, Estrin D.Adaptive beacon placement[A]. In Proceedings of the 2lth International Conference on Distributed Computing Systems[C]. Phoenix, AZ, Apr. 200l:489-498
[14] Meguerdichian S, Koushanfar F, Qu G, et a1. Exposure in wireless Ad hoc sensornetworks[A]. Proc. of 7th Annual International Conference on Mobile Computing and Networking (MobiCom’01)[C]. July 2006:139-150
[15] Couqueur Phipalanasuphom V, Ramanathan P, et a1. Sensor deployment strategy for target detection[A]. Proceeding of The First ACM International Workshop on Wireless Sensor Networks and Applications, WSNA’02[C], Atlanta, Georgia, USA,September 28,2002: 42-48
[16] Slijepcevic S, Potkonjak K. Power efficient organization of wireless sensor networks[A]. Communications IEEE International Conference on 11-14 June 200l, 2:472-476
[17] Liu J, Cheung P, et a1. A dual-space approach to tracking and sensor management in wireless sensor networks[A]. WSNA'02[C], Atlanta, Georgia, USA, September 28, 2002:131-139
[18] Cerpa A, Elson J, Hamilton M, et al. Habitat monitoring: application driver for wireless communications technology [R]. UCLA Computer Science Technical Report 2002, 3, December 2000
[19] Di Tian, Georganas N D. A node scheduling scheme for energy conservation in large wireless sensor networks[J]. Wireless Communications and Mobile Computing, 2003, 3(2):271-290
[20] Ye F, Zhong G, Lu S, et al. Energy efficient robust sensing coverage in large sensor networks[R]. UCLA Technical report 2002:171-179
[21] Varshney P. Distributed Detection and Data Fusion[M]. Spinger-Verlag, New York, 2006:160-173
[22] Li D, Wong K, Hu Y, et al. Detection, classification and tracking of targets in distributed sensor networks[J]. IEEE Signal Processing Magazine, 2002, 19(2):17-29
[23] Meguerdichian S, Slijepcevic S, Karayan V, et a1. Localized algorithms in wireless Ad-Hoc networks: Location discovery and sensor exposure[A]. Proceedings of the 2001 ACM International Symposium on Mobile Ad Hoc Networking & Computing[C]. Long Beach, USA: ACM Press, 2001:106-116
[24] Winfield A F T. Distributed sensing and data collection via broken Ad hoc wireless connected networks of mobile robots, in Distributed Autonomous Robotic Systems4,eds. LE Parker, G Bekey & J Barhen, Springer-Verlag, 2000:273-282
[25] Nojeong H, Varshney P K. An intelligent deployment and clustering algorithm for a distributed mobile sensor network[A]. IEEE International Conference on Systems, Man and Cybernetics, Oct. 5-8, 2003, 5:4576-4581
[26] Jindong Tan. Multiple vehicles for sensor network area coverage [A]. Proceedings of the 5th world congress on intelligent control and automation[C]. Hangzhou, China, June 15-19, 2004:4666-4670
[27] Zou Y, Chakrabarty K. Sensor deployment and target localization based on virtual forces [A]. in Proc. IEEE INFOCOM Conference[C], 2003:1293-1303
[28] Howard A , Matari M J, Sukhatme G S. Mobile sensor network deployment using potential fields: A distributed, scalable solution to the area coverage problem[A]. The 6th International Conference on Distributed Autonomous Robotic Systems (DARS’02)[C], Fukuoka, Japan, June 25-27, 2002:299-308
[29] Frost Gorder. Sizing up smart dust. IEEE Computational Science and Engineering, Volume 5, Issue 6, Nov.-Dec. 2003:6-9
[30] D W Gage. Command control for many-robot systems. The Nineteenth Annul AUVS Technical Symposium in AUVS-92, Huntsville, Alabama, USA. June 2002: 22-24
[31] O Khatib. Real-time obstacle avoidance for manipulators and mobile robots. International Journal of Robotics Research, 5(1):90-98, 1986
[32] Parlaktuna O, Bakla B, Ozkan M. Mobile robot navigation using fuzzy logic methods. Proceedings of the IEEE 13th Conference on Signal Processing and Communications Applications, 16-18 May 2005:432-435
[33] Blanc G, Mezouar Y, Martinet P. Indoor Navigation of a Wheeled Mobile Robot along Visual Routes. Proceedings of the 2005 IEEE International Conference on Robotics and Automation, 18-22 April 2005:3354-3359
[34] Andrew Howard, Maja J, Mataric, Gaurav S. Mobile Sensor Network Deployment using Potential Fields. A Distributed, Scalable Solution to the Area Coverage Problem. In Proceedings of the 6th International Symposium on Distributed Autonomous Robotics Systems (DARS’02) Fukuoka, Japan, June 25-27, 2002
[35] J H Reif, H Wang. Social potential fields: A distributed behavioral control forautonomous robots. Robotics and Autonomous Systems. vol. 27, 1999: 171-194
[36] M Batalin, G S Sukhatme. Spreading out: A local approach to multi-robot coverage. In 6th International Conference on Distributed Autonomous Robotic Systems (DSRS02), Fukuoka, Japan. 2002:373-382
[37] J L Pearce, P E Rybski, S A Stoeter. Dispersion behaviors for a team of multiple miniature robots. In IEEE International Conference on Robotics and Automation, Taipei, Taiwan, September 2003:1158-1163
[38] Sameera Poduri, Gaurav S, Sukhatme. Constrained Coverage for Mobile Sensor Networks. in Proceedings of the 2004 IEEE International Conference on Robotics and Automation, Volume 1, 2004 :165-171 Vol.1
[39] Nojeong Heo, Varshney P K. Energy-efficient deployment of Intelligent Mobile sensor networks. IEEE Transactions on Systems, Man and Cybernetics, Part A, Volume 35, Issue 1, Jan. 2005:78-92
[40] Zhou S, Wu M, Shu Y. Finding optimal placements for mobile sensors: wireless sensor network topology adjustment. Proceedings of the IEEE 6th Circuits and Systems Symposium on Emerging Technologies: Frontiers of Mobile and Wireless Communication, 2004. Volume 2, 31 May-2 June 2004:529-532 Vol.2
[41] Wang G, Cao G, Porta T L, Zhang W. Sensor relocation in mobile sensor networks. Proceedings of the IEEE 24th Annual Joint Conference of the IEEE Computer and Communications Societies. Volume 4, 13-17 March 2005 :2302-2312 vol. 4
[42] Bin Zhang, Sukhatme G S. Controlling Sensor Density Using Mobility. The Second IEEE Workshop on Embedded Networked Sensors.30-31 May 2005:141-150
[43] Guiling Wang, Guohong Cao, La Porta T. Movement-assisted sensor deployment. Twenty-third AnnualJoint Conference of the IEEE Computer and Communications Societies, Volume 4,7-11 March 2004 :2469-2479 vol.4
[44] Di Tian, N D Georganas. A Coverage-Preserving Node Scheduling Scheme for Large Wireless Sensor Networks[C]. in Proceedings of ACM Workshop on Wireless SensorNetworks and Applications, USA, ACM Press, 2002.124-128
[45] Di Tian, N D Georganas. A coverage-preserving node scheduling scheme for large wireless sensor networks[C]. in Proceedings of ACM Wireless Sensor Network andApplication Workshop 2002, 1(1): 23-28
[46] X Wang, G Xing, Y Zhang. Integrated Coverage and Connectivity Con guration in Wireless Sensor Networks [C]. In: First ACM Conference on Embedded Networked Sensor Systems. USA:ACM Press, 2003. 234-23
[47] T Clouqueur, V Phipatanasuphorn, P Ramanathan. Sensor deployment strategy for target detection. in Proceedings of the 1st ACM international workshop on Wireless sensor networks and applications, ACM Press, 2002:42-48
[48] S S Dhillon, K Chakrabarty S, Iyengar S. Sensor placement for grid coverage under imprecise detections. Proc. 5th ISIF Int. Conf. on Information Fusion (FUSION’02, Annapolis MD, July 2002): 1581-1587
[49] Meguerdichian S, Koushanfar F, Potkonjak M, Srivastava M B. Coverage problems in wireless ad-hoc sensor network. In Proc. of the IEEE INFOCOM. Anchorage, IEEE Press, 2006:1380-1387
[50] Meguerdichian S, Koushanfar F, Qu G, Potkonjak M. Exposure in wireless ad-hoc sensor networks. In Proc. of the ACM Int'06 Conf. on Mobile Computing and Networking (MobiCom), New York, ACM Press, 2006:139-150
[51] Poduri S, Sukhatme G S. Constrained coverage for mobile sensor networks. Robotics and Automation. in Proceedings of ICRA '04. IEEE International Conference on Volume 1, 2004:165-171 Vol.1
[52] Zou Y, Krishnendu Chakrabarty. Sensor deployment and target localization based on virtual forces. INFOCOM 2003. Twenty-Second Annual Joint Conference of the IEEE Computer and Communications Societies. IEEE Volume 2, 30 March-3 April 2003 :1293-1303 vol.2
[53] X Y Li, P J Wan, Y Wang. Localized Delaunay triangulation with application in ad-hoc wireless networks. Parallel and Distributed Systems, IEEE Transactions on Volume 14, Issue Oct. 10 2003 :1035-1047
[54] Poduri S, Sukhatme G S. Constrained coverage for mobile sensor networks. Robotics and Automation, 2004. in Proceeding of ICRA '04, 2004 IEEE International Conference on Volume 1, 2004 Page(s):165-171 Vol.1
[55] Benyuan Liu, Towsley D. A study of the coverage of large-scale sensor networks.Mobile Ad-hoc and Sensor Systems, 2004 IEEE International Conference on Oct. 25-27, 2004:475-483
[2]芦东昕,徐文龙,王利存.无线传感器网络.工业控制计算机, 2005年第18卷第4期24-25
[3]任丰原,黄海宁,林闯.无线传感器网络.软件学报, Vol.14 No.7
[4]盛超华,陈章龙.无线传感器网络及应用.微型电脑应用, 2005年第21卷第6期10-13
[5]韩立锋.无线传感器网络技术.网络通信, 2005年第4期15-17
[6]滑楠,史浩山,吴健.无线传感器网络主动QoS机制研究.计算机工程与应用, 2005 Vol.14 120-137
[7]马祖长,孙怡宁,梅涛.无线传感器网络综述.通信学报, 2004年4月第25卷第4期114-124
[8]李国华,沈树群,自组织无线传感器网络的研究.数据通信, 2004年第4期1-4
[9]刘刚,周兴社,谷建华,李志刚.自组织自适应无线传感器网络理论研究.计算机应用研究, 2005年第5期30-33
[10] O’Rourke J.Art gallery theorem and algorithms[M].New York: Oxford University Press, l997
[11] Meguerdichian S, Koushanfar F, Potkonjak M, et al. Coverage problems in wireless Ad-hoc sensor networks [J]. INFOCOM’01, 2006, (3):1380-1387
[12] Chakrabarty K, lyengar S, Qi H, et al. Grid coverage for surveillance and target location in distributed sensor networks [J]. IEEE Trans. on Computers, 2002, 51(12): l448-l453
[13] Bulusu N, Heidemann J, Estrin D.Adaptive beacon placement[A]. In Proceedings of the 2lth International Conference on Distributed Computing Systems[C]. Phoenix, AZ, Apr. 200l:489-498
[14] Meguerdichian S, Koushanfar F, Qu G, et a1. Exposure in wireless Ad hoc sensornetworks[A]. Proc. of 7th Annual International Conference on Mobile Computing and Networking (MobiCom’01)[C]. July 2006:139-150
[15] Couqueur Phipalanasuphom V, Ramanathan P, et a1. Sensor deployment strategy for target detection[A]. Proceeding of The First ACM International Workshop on Wireless Sensor Networks and Applications, WSNA’02[C], Atlanta, Georgia, USA,September 28,2002: 42-48
[16] Slijepcevic S, Potkonjak K. Power efficient organization of wireless sensor networks[A]. Communications IEEE International Conference on 11-14 June 200l, 2:472-476
[17] Liu J, Cheung P, et a1. A dual-space approach to tracking and sensor management in wireless sensor networks[A]. WSNA'02[C], Atlanta, Georgia, USA, September 28, 2002:131-139
[18] Cerpa A, Elson J, Hamilton M, et al. Habitat monitoring: application driver for wireless communications technology [R]. UCLA Computer Science Technical Report 2002, 3, December 2000
[19] Di Tian, Georganas N D. A node scheduling scheme for energy conservation in large wireless sensor networks[J]. Wireless Communications and Mobile Computing, 2003, 3(2):271-290
[20] Ye F, Zhong G, Lu S, et al. Energy efficient robust sensing coverage in large sensor networks[R]. UCLA Technical report 2002:171-179
[21] Varshney P. Distributed Detection and Data Fusion[M]. Spinger-Verlag, New York, 2006:160-173
[22] Li D, Wong K, Hu Y, et al. Detection, classification and tracking of targets in distributed sensor networks[J]. IEEE Signal Processing Magazine, 2002, 19(2):17-29
[23] Meguerdichian S, Slijepcevic S, Karayan V, et a1. Localized algorithms in wireless Ad-Hoc networks: Location discovery and sensor exposure[A]. Proceedings of the 2001 ACM International Symposium on Mobile Ad Hoc Networking & Computing[C]. Long Beach, USA: ACM Press, 2001:106-116
[24] Winfield A F T. Distributed sensing and data collection via broken Ad hoc wireless connected networks of mobile robots, in Distributed Autonomous Robotic Systems4,eds. LE Parker, G Bekey & J Barhen, Springer-Verlag, 2000:273-282
[25] Nojeong H, Varshney P K. An intelligent deployment and clustering algorithm for a distributed mobile sensor network[A]. IEEE International Conference on Systems, Man and Cybernetics, Oct. 5-8, 2003, 5:4576-4581
[26] Jindong Tan. Multiple vehicles for sensor network area coverage [A]. Proceedings of the 5th world congress on intelligent control and automation[C]. Hangzhou, China, June 15-19, 2004:4666-4670
[27] Zou Y, Chakrabarty K. Sensor deployment and target localization based on virtual forces [A]. in Proc. IEEE INFOCOM Conference[C], 2003:1293-1303
[28] Howard A , Matari M J, Sukhatme G S. Mobile sensor network deployment using potential fields: A distributed, scalable solution to the area coverage problem[A]. The 6th International Conference on Distributed Autonomous Robotic Systems (DARS’02)[C], Fukuoka, Japan, June 25-27, 2002:299-308
[29] Frost Gorder. Sizing up smart dust. IEEE Computational Science and Engineering, Volume 5, Issue 6, Nov.-Dec. 2003:6-9
[30] D W Gage. Command control for many-robot systems. The Nineteenth Annul AUVS Technical Symposium in AUVS-92, Huntsville, Alabama, USA. June 2002: 22-24
[31] O Khatib. Real-time obstacle avoidance for manipulators and mobile robots. International Journal of Robotics Research, 5(1):90-98, 1986
[32] Parlaktuna O, Bakla B, Ozkan M. Mobile robot navigation using fuzzy logic methods. Proceedings of the IEEE 13th Conference on Signal Processing and Communications Applications, 16-18 May 2005:432-435
[33] Blanc G, Mezouar Y, Martinet P. Indoor Navigation of a Wheeled Mobile Robot along Visual Routes. Proceedings of the 2005 IEEE International Conference on Robotics and Automation, 18-22 April 2005:3354-3359
[34] Andrew Howard, Maja J, Mataric, Gaurav S. Mobile Sensor Network Deployment using Potential Fields. A Distributed, Scalable Solution to the Area Coverage Problem. In Proceedings of the 6th International Symposium on Distributed Autonomous Robotics Systems (DARS’02) Fukuoka, Japan, June 25-27, 2002
[35] J H Reif, H Wang. Social potential fields: A distributed behavioral control forautonomous robots. Robotics and Autonomous Systems. vol. 27, 1999: 171-194
[36] M Batalin, G S Sukhatme. Spreading out: A local approach to multi-robot coverage. In 6th International Conference on Distributed Autonomous Robotic Systems (DSRS02), Fukuoka, Japan. 2002:373-382
[37] J L Pearce, P E Rybski, S A Stoeter. Dispersion behaviors for a team of multiple miniature robots. In IEEE International Conference on Robotics and Automation, Taipei, Taiwan, September 2003:1158-1163
[38] Sameera Poduri, Gaurav S, Sukhatme. Constrained Coverage for Mobile Sensor Networks. in Proceedings of the 2004 IEEE International Conference on Robotics and Automation, Volume 1, 2004 :165-171 Vol.1
[39] Nojeong Heo, Varshney P K. Energy-efficient deployment of Intelligent Mobile sensor networks. IEEE Transactions on Systems, Man and Cybernetics, Part A, Volume 35, Issue 1, Jan. 2005:78-92
[40] Zhou S, Wu M, Shu Y. Finding optimal placements for mobile sensors: wireless sensor network topology adjustment. Proceedings of the IEEE 6th Circuits and Systems Symposium on Emerging Technologies: Frontiers of Mobile and Wireless Communication, 2004. Volume 2, 31 May-2 June 2004:529-532 Vol.2
[41] Wang G, Cao G, Porta T L, Zhang W. Sensor relocation in mobile sensor networks. Proceedings of the IEEE 24th Annual Joint Conference of the IEEE Computer and Communications Societies. Volume 4, 13-17 March 2005 :2302-2312 vol. 4
[42] Bin Zhang, Sukhatme G S. Controlling Sensor Density Using Mobility. The Second IEEE Workshop on Embedded Networked Sensors.30-31 May 2005:141-150
[43] Guiling Wang, Guohong Cao, La Porta T. Movement-assisted sensor deployment. Twenty-third AnnualJoint Conference of the IEEE Computer and Communications Societies, Volume 4,7-11 March 2004 :2469-2479 vol.4
[44] Di Tian, N D Georganas. A Coverage-Preserving Node Scheduling Scheme for Large Wireless Sensor Networks[C]. in Proceedings of ACM Workshop on Wireless SensorNetworks and Applications, USA, ACM Press, 2002.124-128
[45] Di Tian, N D Georganas. A coverage-preserving node scheduling scheme for large wireless sensor networks[C]. in Proceedings of ACM Wireless Sensor Network andApplication Workshop 2002, 1(1): 23-28
[46] X Wang, G Xing, Y Zhang. Integrated Coverage and Connectivity Con guration in Wireless Sensor Networks [C]. In: First ACM Conference on Embedded Networked Sensor Systems. USA:ACM Press, 2003. 234-23
[47] T Clouqueur, V Phipatanasuphorn, P Ramanathan. Sensor deployment strategy for target detection. in Proceedings of the 1st ACM international workshop on Wireless sensor networks and applications, ACM Press, 2002:42-48
[48] S S Dhillon, K Chakrabarty S, Iyengar S. Sensor placement for grid coverage under imprecise detections. Proc. 5th ISIF Int. Conf. on Information Fusion (FUSION’02, Annapolis MD, July 2002): 1581-1587
[49] Meguerdichian S, Koushanfar F, Potkonjak M, Srivastava M B. Coverage problems in wireless ad-hoc sensor network. In Proc. of the IEEE INFOCOM. Anchorage, IEEE Press, 2006:1380-1387
[50] Meguerdichian S, Koushanfar F, Qu G, Potkonjak M. Exposure in wireless ad-hoc sensor networks. In Proc. of the ACM Int'06 Conf. on Mobile Computing and Networking (MobiCom), New York, ACM Press, 2006:139-150
[51] Poduri S, Sukhatme G S. Constrained coverage for mobile sensor networks. Robotics and Automation. in Proceedings of ICRA '04. IEEE International Conference on Volume 1, 2004:165-171 Vol.1
[52] Zou Y, Krishnendu Chakrabarty. Sensor deployment and target localization based on virtual forces. INFOCOM 2003. Twenty-Second Annual Joint Conference of the IEEE Computer and Communications Societies. IEEE Volume 2, 30 March-3 April 2003 :1293-1303 vol.2
[53] X Y Li, P J Wan, Y Wang. Localized Delaunay triangulation with application in ad-hoc wireless networks. Parallel and Distributed Systems, IEEE Transactions on Volume 14, Issue Oct. 10 2003 :1035-1047
[54] Poduri S, Sukhatme G S. Constrained coverage for mobile sensor networks. Robotics and Automation, 2004. in Proceeding of ICRA '04, 2004 IEEE International Conference on Volume 1, 2004 Page(s):165-171 Vol.1
[55] Benyuan Liu, Towsley D. A study of the coverage of large-scale sensor networks.Mobile Ad-hoc and Sensor Systems, 2004 IEEE International Conference on Oct. 25-27, 2004:475-483