无线传感器网络中节点定位算法的研究
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摘要
早在上世纪七十年代末,美国国防部高级研究计划署(DARPA)就提出了无线传感器网络的最初构想。随着近三十年来微电机系统MEMS(micro-electro-mechanical systems)、嵌入式系统、处理器、无线电技术以及存储技术的巨大进步,新一代无线传感器网络应运而生。无线传感器网络通常由大量具有有限的感知、计算、存储和无线通信能力的微小节点构成,当将这些节点以适当的方式组成网络,并将它们的输出有机地关联与融合时,整个网络可提供远高于单个节点的强大功能。无线传感器网络可广泛应用于环境监测、工业过程控制、战场监视、抢险救灾、反恐等多种场合。美国国家研究委员会在一篇报告中指出,“该网络在全社会的普及将使此前信息革命中发生的一切重大事件相形见绌”。
无线传感器网络已成为近几年的研究热点,其中网络路由、时间同步、节点定位、拓扑控制及传感器网络应用等成为研究的重点。节点定位是无线传感器网络的一项基本能力。传感器节点从物理环境中采集的数据只有同位置信息联系在一起才是有意义的,同时节点位置还在目标定位/跟踪、提高路由效率等方面发挥着重要的作用。然而,为传感器网络设计和实现一个“最佳”的定位算法是一件非常困难的事情,主要原因在于传感器网络的规模可能很大(成千上百个节点),而计算、通信、存储能力及能源都非常有限,这使得常见的定位策略(如利用GPS系统、手工配置位置等)无法应用到传感器网络中。
目前,学术界已经提出了各种各样的节点定位算法,这些算法大致分为基于测距的定位算法和非基于测距的定位两类。基于测距的定位算法使用某种测量技术得到节点间关于距离或角度的估计值,然后采用三边测量法或三角测量法等几何方法进行定位。非基于测距的定位算法利用接收到的信号强度或节点间的无线连接来判断节点间的远近关系或邻居关系,进而粗略地进行定位。目前最常见的测距方法是利用节点配备的无线电收发器,通过接收到的信号强度并利用信号的传播模型来估计距离,这个模型假定无线电信号的传输是各向同性的。然而,越来越多的研究表明,在无线传感器网络这种由密集的低功率节点组成的环境中,无线信号的传播严重偏离理想模型,接收信号强度严重依赖方向,而且随节点及环境的不同而不同,因而完全没有可能仅根据接收到的信号强度来推断距离。这意味着目前所有依赖于理想信号传播模型的定位算法都需要重新考虑。
由于传感器网络通常部署在无人看护的环境,采用无线通信方式,并且节点的能力及资源非常有限,特别容易受到各种安全攻击。针对节点定位的攻击多为位置及距离欺骗攻击,比如假冒合法节点发布虚假的参考位置信息,通过破坏信号的传播时间、强度或角度来误导测量结果等。然而,目前无线传感器网络中大多数的节点定位算法不具有抵抗安全攻击的能力,少数已经提出的安全定位算法或者只适用于特定种类的安全攻击,或者算法的计算及通信开销很大,不适合能源紧缺的无线传感器网络。
本文研究无线传感器网络的节点定位问题。本文的第一个工作是利用一个仿真实际信号传播特性的无线电信号不规则模型RIM(Radio IrregularityModel)建立模拟实验环境,通过大量的仿真实验研究了接收信号强度、链路对称性及距离之间的映射关系,在此基础上设计并实现了一个基于链路状态的节点定位算法LSBA(Link-State Based Annulus),并在仿真实验环境中与其它四个典型的同类算法Centroid、DV-HOP、Amorphous和APIT在定位精度、算法收敛速度、计算复杂度和通信复杂度四个方面进行了全面比较。这也是这四个算法在模拟实验环境中首次进行全面的性能比较。实验结果表明在具有适量参考节点的无线传感器网络中,LSBA具有最佳的综合性能,并且LSBA对节点的不规则分布也有很好的适应性。
本文的第二项工作是设计并实现了一个能够抵御各种位置和距离攻击并能适应节点与环境异常的鲁棒的节点定位算法Bilateration。该算法将位置或距离攻击导致的虚假位置或距离看成是有误差的信息,而节点出错或局部环境异常造成的结果也是出现位置或距离误差,为此Bilateration采用统一的方法来处理这三种情况。首先根据正常的位置与距离应有的几何关系区分出可能是正确的和错误的(即误差太大的)信息,然后只利用可能是正确的信息进行节点定位。本文将Bilateration与基于三边测量法的三个典型算法(有过滤能力和没有过滤能力)进行了比较,仿真实验表明在测量噪声受限的传感器网络中,Bilateration具有最好的定位精度和最小的计算复杂度。
As early as the late 1970s, the U.S. Defense Advanced Research Projects Agency (DARPA) presents the original idea of Wireless Sensor Networks (WSNs). With nearly three decades' development of MEMS (micro-electro-mechanical systems), embedded systems, processors, wireless technology and storage technology, a new generation of wireless sensor networks have emerged. Wireless sensor networks are composed of numerous tiny sensor nodes, which have limited sensing, computing, storage and communication capabilities. When these nodes are organized in an appropriate manner, and their output are organically associated and integrated, the whole network can provide much higher ability than a single node. Wireless sensor networks can be widely used in environmental monitoring, industrial control, battlefield surveillance, disaster relief and rescue, anti-terrorism and other occasions. The U.S. National Research Council reports that "The use of Embedded (Networked) Systems throughout society could well dwarf previous milestones in the information revolution."
Recent years, wireless sensor networks have become a hot research spot, in which routing protocol, synchronization, node localization, topology control and applications are the important research fields. Node localization is a basic capacity of wireless sensor networks. WSNs are essentially intended to observe spatio-temporal characteristics of the physical world. It is meaningful only when the collected data are associated with their locations. Locations of sensor nodes are fundamental to providing location stamps, locating and tracking point objects, forming clusters, and facilitating routing, etc. However, it is really difficult to design and implement a "best" positioning algorithm, mainly because of the magnificent size of WSNs (hundreds of thousands of nodes) and the limited computing, communications, storage capacity and energy, which makes common positioning strategies (such as GPS or manual configuration, etc.) can not be applied to sensor networks.
At present, numerous localization algorithms have been proposed, these algorithms are broadly divided into the "range-based" and "range-free". Range-based approaches are using a measurement technology to get the accurate distance or angle measurements, and then locate the unknown nodes with trilateration ( mul-tilateration ) or triangulation methods. Range-free approaches normally rely on proximity, near-far information or less accurate distance estimation to infer the lo- cations of unknown nodes. The most common method is to use signal propagation model to estimate the distance, as the transceiver is the only available ranging device for most of the common sensor nodes, and the model usually is isotropic. However, an increasing number of studies show that in such a intensive low-power WSNs, the propagation of the wireless signal leads a serious departure from the ideal model. Receiver signal strength is heavily dependent on the direction and is different with different nodes or different environment. Therefore it is unlikely to infer the distance according to the received signal strength. This means that all the localization methods depending on the ideal propagation model need to be reconsidered.
As WSNs usually run in open environments, use wireless communications and only have very limited resources, it is vulnerable to various kinds of attacks. Attackers may disseminate false reference positions in the network, or mislead unknown nodes to get false distance/angle measurements by tricks like modifying distance, jamming communication and creating wormhole. However, most of the node localization algorithm does not have the capacity to resist attacks; and a few secure localization algorithms can be applied only to specific types, or the computational complexity and communication complexity are very high, which are not suitable for power constrained WSNs.
Through this dissertation, we study the node localization. The first work of this dissertation is to build a simulation environment according to the RIM (Radio Irregularity Model). After a large number of simulated experiments, we got the relationship between RSS and distance with different link status. Based on the previous research work, we provide a Link-State Based Annulus (LSBA) localization algorithm, and then gives a panorama of performance comparison among LSBA and other four localization algorithms: Centroid, DV-HOP, Amorphous and APIT in terms of estimation accuracy, convergence speed, computational complexity and communication cost in the simulated realistic environment. Simulation results show that LSBA achieves the best tradeoff among all the four metrics in WSNs with moderate number of anchors, and has good adaptability to irregular node deployment as well.
The second work of this paper is to design and implement a robust node localization algorithm, which is capable of dealing with various location and distance attacks and as well as other kinds of information distortion caused by node malfunction or abnormal environmental noise. Bilateration deals with location attacks, node malfunction and exceptional measurements in a unified way by considering the set of samples consisting of reasonable samples and unreasonable samples and trying to use reasonable samples to locate unknown nodes. It first distinguish the possible correct or false (that is, too much error) information; then it only use the possibly correct information to do localization. This dissertation also evaluates and compares Bilateration with three multilateration based localization algorithms, and the simulation results show that Bilateration achieves the best comprehensive performance and is more suitable to real wireless sensor networks.
无线传感器网络已成为近几年的研究热点,其中网络路由、时间同步、节点定位、拓扑控制及传感器网络应用等成为研究的重点。节点定位是无线传感器网络的一项基本能力。传感器节点从物理环境中采集的数据只有同位置信息联系在一起才是有意义的,同时节点位置还在目标定位/跟踪、提高路由效率等方面发挥着重要的作用。然而,为传感器网络设计和实现一个“最佳”的定位算法是一件非常困难的事情,主要原因在于传感器网络的规模可能很大(成千上百个节点),而计算、通信、存储能力及能源都非常有限,这使得常见的定位策略(如利用GPS系统、手工配置位置等)无法应用到传感器网络中。
目前,学术界已经提出了各种各样的节点定位算法,这些算法大致分为基于测距的定位算法和非基于测距的定位两类。基于测距的定位算法使用某种测量技术得到节点间关于距离或角度的估计值,然后采用三边测量法或三角测量法等几何方法进行定位。非基于测距的定位算法利用接收到的信号强度或节点间的无线连接来判断节点间的远近关系或邻居关系,进而粗略地进行定位。目前最常见的测距方法是利用节点配备的无线电收发器,通过接收到的信号强度并利用信号的传播模型来估计距离,这个模型假定无线电信号的传输是各向同性的。然而,越来越多的研究表明,在无线传感器网络这种由密集的低功率节点组成的环境中,无线信号的传播严重偏离理想模型,接收信号强度严重依赖方向,而且随节点及环境的不同而不同,因而完全没有可能仅根据接收到的信号强度来推断距离。这意味着目前所有依赖于理想信号传播模型的定位算法都需要重新考虑。
由于传感器网络通常部署在无人看护的环境,采用无线通信方式,并且节点的能力及资源非常有限,特别容易受到各种安全攻击。针对节点定位的攻击多为位置及距离欺骗攻击,比如假冒合法节点发布虚假的参考位置信息,通过破坏信号的传播时间、强度或角度来误导测量结果等。然而,目前无线传感器网络中大多数的节点定位算法不具有抵抗安全攻击的能力,少数已经提出的安全定位算法或者只适用于特定种类的安全攻击,或者算法的计算及通信开销很大,不适合能源紧缺的无线传感器网络。
本文研究无线传感器网络的节点定位问题。本文的第一个工作是利用一个仿真实际信号传播特性的无线电信号不规则模型RIM(Radio IrregularityModel)建立模拟实验环境,通过大量的仿真实验研究了接收信号强度、链路对称性及距离之间的映射关系,在此基础上设计并实现了一个基于链路状态的节点定位算法LSBA(Link-State Based Annulus),并在仿真实验环境中与其它四个典型的同类算法Centroid、DV-HOP、Amorphous和APIT在定位精度、算法收敛速度、计算复杂度和通信复杂度四个方面进行了全面比较。这也是这四个算法在模拟实验环境中首次进行全面的性能比较。实验结果表明在具有适量参考节点的无线传感器网络中,LSBA具有最佳的综合性能,并且LSBA对节点的不规则分布也有很好的适应性。
本文的第二项工作是设计并实现了一个能够抵御各种位置和距离攻击并能适应节点与环境异常的鲁棒的节点定位算法Bilateration。该算法将位置或距离攻击导致的虚假位置或距离看成是有误差的信息,而节点出错或局部环境异常造成的结果也是出现位置或距离误差,为此Bilateration采用统一的方法来处理这三种情况。首先根据正常的位置与距离应有的几何关系区分出可能是正确的和错误的(即误差太大的)信息,然后只利用可能是正确的信息进行节点定位。本文将Bilateration与基于三边测量法的三个典型算法(有过滤能力和没有过滤能力)进行了比较,仿真实验表明在测量噪声受限的传感器网络中,Bilateration具有最好的定位精度和最小的计算复杂度。
As early as the late 1970s, the U.S. Defense Advanced Research Projects Agency (DARPA) presents the original idea of Wireless Sensor Networks (WSNs). With nearly three decades' development of MEMS (micro-electro-mechanical systems), embedded systems, processors, wireless technology and storage technology, a new generation of wireless sensor networks have emerged. Wireless sensor networks are composed of numerous tiny sensor nodes, which have limited sensing, computing, storage and communication capabilities. When these nodes are organized in an appropriate manner, and their output are organically associated and integrated, the whole network can provide much higher ability than a single node. Wireless sensor networks can be widely used in environmental monitoring, industrial control, battlefield surveillance, disaster relief and rescue, anti-terrorism and other occasions. The U.S. National Research Council reports that "The use of Embedded (Networked) Systems throughout society could well dwarf previous milestones in the information revolution."
Recent years, wireless sensor networks have become a hot research spot, in which routing protocol, synchronization, node localization, topology control and applications are the important research fields. Node localization is a basic capacity of wireless sensor networks. WSNs are essentially intended to observe spatio-temporal characteristics of the physical world. It is meaningful only when the collected data are associated with their locations. Locations of sensor nodes are fundamental to providing location stamps, locating and tracking point objects, forming clusters, and facilitating routing, etc. However, it is really difficult to design and implement a "best" positioning algorithm, mainly because of the magnificent size of WSNs (hundreds of thousands of nodes) and the limited computing, communications, storage capacity and energy, which makes common positioning strategies (such as GPS or manual configuration, etc.) can not be applied to sensor networks.
At present, numerous localization algorithms have been proposed, these algorithms are broadly divided into the "range-based" and "range-free". Range-based approaches are using a measurement technology to get the accurate distance or angle measurements, and then locate the unknown nodes with trilateration ( mul-tilateration ) or triangulation methods. Range-free approaches normally rely on proximity, near-far information or less accurate distance estimation to infer the lo- cations of unknown nodes. The most common method is to use signal propagation model to estimate the distance, as the transceiver is the only available ranging device for most of the common sensor nodes, and the model usually is isotropic. However, an increasing number of studies show that in such a intensive low-power WSNs, the propagation of the wireless signal leads a serious departure from the ideal model. Receiver signal strength is heavily dependent on the direction and is different with different nodes or different environment. Therefore it is unlikely to infer the distance according to the received signal strength. This means that all the localization methods depending on the ideal propagation model need to be reconsidered.
As WSNs usually run in open environments, use wireless communications and only have very limited resources, it is vulnerable to various kinds of attacks. Attackers may disseminate false reference positions in the network, or mislead unknown nodes to get false distance/angle measurements by tricks like modifying distance, jamming communication and creating wormhole. However, most of the node localization algorithm does not have the capacity to resist attacks; and a few secure localization algorithms can be applied only to specific types, or the computational complexity and communication complexity are very high, which are not suitable for power constrained WSNs.
Through this dissertation, we study the node localization. The first work of this dissertation is to build a simulation environment according to the RIM (Radio Irregularity Model). After a large number of simulated experiments, we got the relationship between RSS and distance with different link status. Based on the previous research work, we provide a Link-State Based Annulus (LSBA) localization algorithm, and then gives a panorama of performance comparison among LSBA and other four localization algorithms: Centroid, DV-HOP, Amorphous and APIT in terms of estimation accuracy, convergence speed, computational complexity and communication cost in the simulated realistic environment. Simulation results show that LSBA achieves the best tradeoff among all the four metrics in WSNs with moderate number of anchors, and has good adaptability to irregular node deployment as well.
The second work of this paper is to design and implement a robust node localization algorithm, which is capable of dealing with various location and distance attacks and as well as other kinds of information distortion caused by node malfunction or abnormal environmental noise. Bilateration deals with location attacks, node malfunction and exceptional measurements in a unified way by considering the set of samples consisting of reasonable samples and unreasonable samples and trying to use reasonable samples to locate unknown nodes. It first distinguish the possible correct or false (that is, too much error) information; then it only use the possibly correct information to do localization. This dissertation also evaluates and compares Bilateration with three multilateration based localization algorithms, and the simulation results show that Bilateration achieves the best comprehensive performance and is more suitable to real wireless sensor networks.
引文
[1]S.Meyer and A.Rakotonirainy,"A survey of research on context-aware homes,"in Proceedings of the Workshop on Wearable,Invisible,Context-Aware,Ambient,Pervasive and Ubiquitous Computing,pp.1-9,2003.
[2]G.O.A.Wayne W.Manges and S.F.Smith,"It' s time for sensors to go wireless,"Sensors Magazine,1999.
[3]"Smart dust,http://www.dust-inc.com."
[4]"The wireless integrated network sensors project(wins),http:/www.janet.ucla.edu/wins."
[5]D.E.L.G.M.H.A.Cerpa,J.Elson and J.Zhao,"Habitat monitoring:application driver for wireless communications technology," in Proceedings of the ACM SIGCOMM Workshop on Data Communications in Latin America and the Caribbean,pp.20-41,2001.
[6]D.C.J.Lundquist and M.Dettinger,"Meteorology and hydrology in yosemite national park:A sensor network application," in Proceedings of the 2nd International Workshop on Information Processing in Sensor Networks(IPSN' 03),pp.518-528,2003.
[7]R.S.D.C.A.Mainwaring,J.Polastre and J.Anderson,"Wireless sensor networks for habitat monitoring," in Proceedings of the 1st ACM International Workshop on Wireless Sensor Networks and Applications(WSNA' 02),pp.88-97,2002.
[8]R.G.C.Intanagonwiwat and D.Estrin,"Directed diffusion:A scalable and robust communication paradigm for sensor networks," in Proceedings of the 6th International Conference on Mobile Computing and Networking(MobiCom' 00),pp.56-66,2000.
[9]R.C.Shah and J.Rabaey,"Energy aware routing for low energy ad hoc sensor networks," in Proceedings of the IEEE Wireless Communications and Networking Conference(WCNC' 02),pp.635-644,2002.
[10]E.D.N.B.Priyantha,H.Balakrishnan and S.Teller,"Anchor-free distributed localization in sensor networks," 2003.
[11]R.G.C.Intanagonwiwat and D.Estrin,"Directed diffusion:A scalable and robust communication paradigm for sensor networks," in Proceedings of the 6th International Conference on Mobile Computing and Networking(MobiCom' 00),pp.56-66,2000.
[12]J.A.Q.Li and D.Rus,"Hierarchical power-routing in sensor networks," in Proceedings of the DIMA CS Workshop on Pervasive Networking,Center for Discrete Mathematics(?)Theoretical Computer Science,2001.
[13]R.Ramanathan and R.Rosales-Hain,"Topology control of multihop wireless networks using transmit power adjustment," in Proceedings of the 19th Joint Conference of the IEEE Computer and Communications Societies(INFOCOM' 00),2000.
[14]J.H.P.Buonodonna and D.Culler,"Active message communication for tiny net- worked sensors," in Proceedings of the 20th Joint Conference of the IEEE Computer and Communications Societies(INFOCOM' 01),2001.
[15]J.H.et al,"System architecture directions for networked sensors," in Proceedings of the 9th International Conference on Architectural Support for Programming Languages and Operating Systems(ASPLOS' 00),2000.
[16]N.A.-G.S.Tilak and W.Heinzelman,"Infrastructure tradeoffs for sensor networks,"in Proceedings of the 1st ACM International Workshop on Wireless Sensor Networks and Applications(WSNA' 02),pp.19-57,2002.
[17]Y.S.I.F.Akyildiz,W.Su,"A survey on sensor networks," IEEE Communications Magazine,vol.40,pp.102-114,2002.
[18]G.J.Pottie and W.J.Kaiser,"Wireless integrated network sensors," Communications of the ACM,vol.43,pp.51-58,2000.
[19]A.C.J.Albowicz and L.Zhang,"Recursive position estimation in sensor networks,"in Proceedings of the 9th International Conference on Network Protocols,pp.35-41,2001.
[20]P.Bergamo and G.Mazzini,"Localization in sensor networks with fading and mobility," in Proceedings of the 13th IEEE International Symposium on Personal,Indoor and Mobile Radio Communications(PIMRC' 02),pp.750-754,2002.
[21]N.Bulusu,J.Heidemann,and D.Estrin,"Gps-less low cost outdoor localization for very small devices," 2000.
[22]N.Bulusu,J.Heidemann,and D.Estrin,"Adaptive beacon placement," in Proceedings of the 21st International Conference on Distributed Computing Systems,pp.489-498,2001.
[23]L.Girod and D.Estrin,"Robust range estimation using acoustic and multimodal sensing," in Proceedi.ngs of the IEEE/RSJ International Conference on Intelligent Robots and Systems(IROS' 01),pp.1312-1320,2001.
[24]J.Heidemann and N.Bulusu,"Using geospatial information in sensor networks,"in Pwceedings of the Workshop on Intersections between Geospatial Information and Information Technology,2001.
[25]R.Iyengar and B.Sikdar,"Scalable and distributed gps free positioning for sensor networks," in Proceedings of the IEEE International Conference on Communications (ICC' 03),pp.338-342,2003.
[26]D.Niculescu and B.Nath,"Ad-hoc positioning system(aps)," in Proc.of IEEE Global Communications Conference(GLOBECOM),pp.2926-2931,2001.
[27]J.R.C.Savarese and J.Beutel,"Locationing in distributed ad-hoc wireless sensor networks," in Proceedings of the International Conference on Acoustics,Speech and Signal Processing(ICASSP' 01),2001.
[28]A.Savvides,C.-C.Han,and M.B.Strivastava,"Dynamic fine-grained localization in ad-hoc networks of sensors," in Mobile Computing and Networking,pp.166-179,2001.
[29]G.P.D.Estrin,L.Girod and M.Srivastava,"Instrumenting the world with wireless sensor networks," in Proceedings of the International Conference on Acoustics,Speech and Signal Processing(ICASSP' 01),2001.
[30]R.H.K.J.M.Kahn and K.S.J.Pister,"Next century challenges:Mobile networking for "smart dust"," in Proceedings of the 5th International Conference on Mobile Computing and Networking(MobiCom' 99),1999.
[31]"Geographical and energy aware routing:a recursive data dissemination protocol for wireless sensor networks," 2001.
[32]H.L.B.Hofmann-Wellenhof and J.Collins,Global Positioning System:Theory and Practice.fourth edition.Springer-Verlag,1997.
[33]Y.Shang and W.Ruml,"Improved rods-based localization," in Proceedings of the 23rd Joint Conference of the IEEE Computer and Communications Societies(INFOCOM'04),2004.
[34]P.Bahl and V.N.Padmanabhan,"RADAR:An -building RF-based user location and tracking system," in Proc.of International Conference of the IEEE Computer and Communications Societies(INFOCOM),pp.775-784,Mar.2000.
[35]G.yao Jin,X.yi Lu,and M.-S.Park,"Spoton:An indoor 3d location sensing technology based on rf signal strength," in Proceedings of the IEEE International Conference on Sensor Networks,Ubiquitous,and Trustworthy Computing(SUTC' 06),2000.
[36]M.P.S.Meguerdichian,F.Koushanfar and M.Srivastava,"Coverage problems in wireless ad-hoc sensor networks," in Proceedings of the 20th Joint Conference of the IEEE Computer and Communications Societies(INFOCOM' 01),2001.
[37]M.H.S.Capkun and J.Hubaux,"Gps-free positioning in mobile ad-hoc networks,"in n Proceedings of the 34th Hawaii International Conference on System Sciences (HICSS' 01),2001.
[38]S.Meguerdichian,S.Slijepcevic,V.Karayan,and M.Potkonjak,"Localized algorithms in wireless ad-hoc networks:location discovery and sensor exposure," in MOBIHOC 2001.
[39]T.He,C.Huang,B.Blum,J.Stankovic,and T.Abdelzaher,"Range-free localization schemes in large scale sensor networks," in MobiCom 2003.,pp.81-95,2003.
[40]M.Sichitiu and V.Ramadurai,"Localization of wireless sensor networks with a mobile beacon," in Proceedings of the 1st IEEE International Conference on Mobile Ad-hoc and Sensor Systems(MASS' 04),pp.174-183,2004.
[41]B.Kusy,A.Ledeczi,M.Maroti,and L.Meertens,"Node-density independent localization,"in Proc.of Information Processing in Sensor Networks(IPSN),2003.
[42]A.Nasipuri and K.Li,"A directionality based location discovery scheme for wireless sensor networks," in Proceedings of the 1st ACM International Workshop on Wire-less Sensor Networks and Applications(WSNA' 02),2002.
[43]P.S.A.W.A.Hatter,A.Hopper and P.Webster,"The anatomy of a contextaware application," in Proceedings of the 5th International Conference on Mobile Computing and Networking(MobiCom' 99),1999.
[44]A.C.N.B.Priyantha and H.Balakrishnan,"The cricket location-support system,"in Proceedings of the 6th International Conference on Mobile Computing and Net-working(MobiCom' 00),2000.
[45]H.P.A.Savvides and M.Srivastava,"The bits and flops of the n-hop multilateration primitive for node localization problems," in Proceedings of the 1st ACM International Workshop on Wireless Sensor Networks and Applications(WSNA' 02),2002.
[46]L.Doherty,K.pister,and L.E.Ghaoui,"Convex position estimation in wireless sensor networks," in Proc.of International Conference of the IEEE Computer and Communications Societies(INFOCOM),pp.1655-1663,Apr.2001.
[47]L.Hu and D.Evans,"Localization for mobile sensor networks," in Proceedings of the 10th annual international conference on Mobile computing and networking.
[48]C.Zhou and B.Krishnamachari,"Localized topology generation mechanisms for self-configuring sensor networks," in Proceedigns of IEEE Global Communications Conference(GLOBECOM' 03),2003.
[49]D.Moore,J.Leonard,D.Rus,and S.Teller,"Robust distributed network localization with noisy range measurements," in Proceedings of the 1st International Conference on Embedded Networked Sensor Systems(SenSys'04),pp.50-61,2004.
[50]S.N.Simic and S.Sastry,"A distributed algorithm for localization in random wireless networks," 2002.
[51]D.D.Culler and M.Strivastava,"Macro-calibration in sensor/actuator networks,"Mobile Networks and Applications,vol.8,pp.463-472,2004.
[52]W.Xu,T.Wood,W.Trappe,and Y.Zhang,"Channel surfing and spatial retreats:defenses against wireless denial of service," in Proceedings of the ACM workshop on Wireless security,pp.80-89,2004.
[53]Y.Hu,A.Perrig,and D.Johnson,"Packet leashes:a defense against wormhole attacks in wireless networks," in INFOCOM 2003,pp.1976-1986,2003.
[54]Z.Li,W.Trappe,Y.Y.Zhang,and B.Nath,"Robust statistical methods for securing wireless localization in sensor networks," in IPSN 2005,pp.91-98,2005.
[55]S.Brands and D.Chaum,"Distance-bounding protocols," in Theory and Application of Cryptographic Techniques,pp.344-359,1993.
[56]N.Sastry,U.Shankar,and D.Wagner,"Secure verification of location claims," in Proceedings of the 2003 ACM workshop on Wireless security,2003.
[57]B.Waters and E.Felten,"Proving the location of tamper resistant devices," 2003.
[58]S.Capkun,L.Buttyan,and J.Hubaux,"Sector:Secure tracking of node encounters in multi-hop wireless networks," in ACM Workshop on Security of Ad Hoc and Sensor Networks(SASN)2003,pp.21-32,2003.
[59]P.Tao,A.Rudys,A.M.Ladd,and D.S.Wallach,"Wireless lan location-sensing for security applications," in Proceedings of the ACM Workshop on Wireless Security,pp.11-20,2003.
[60]E.Gabber and A.Wool,"How to prove where you are:Tracking the location of customer equipment," in A CM Conference on Computer and Communications Security,pp.142-149,1998.
[61]L.Lazos and R.Poovendran,"Serloc:Secure range-independent localization for wireless sensor networks," in Proceedings of the 2004 A CM Workshop on Wireless Security,pp.21-30,2004.
[62]M.G.Kuhn,"An asymmetric security mechanism for navigation signals," in Proceedings of the Information Hiding Workshop,pp.239-252,2004.
[63]D.Liu,P.Ning,and W.Du,"ttack-resistant location estimation in sensor networks,"in IPSN 2005,pp.99-106,2005.
[64]D.S.B.Przydatek and A.Perrig,"Sia:secure information aggregation in sensor networks," in Proceedings of the 1st International Conference on Embedded Networked Sensor Systems(SenSys'03),pp.255-265,2003.
[65]D.Wagner,"Resilient aggregation in sensor networks," in Proceedings of the 2nd ACM workshop on Security of ad hoc and sensor networks(SASN'04),pp.78-87,2004.
[66]K.Langendoen and N.Reijers,"Distributed localization in wireless sensor networks:a quantitative comparison," 2002.
[67]Y.Z.Y.Shang,W.Ruml and M.P.J.Fromherz,"Localization from mere connectivity,"in Proceedings of the 4th acre international symposium on mobile ad hoc networking computing(MobiHoc' 03),pp.201-211,2003.
[68]P.Biswas and Y.Ye,"A distributed method for solving semidefinite programs arising from ad hoc wireless sensor network localization," in Technical report,Dept of Management Science and Engineering,Stanford University,2003.
[69]P.Biswas and Y.Ye,"Semidefinite programming for ad hoc wireless sensor network localization," in Proceedings of the the 4th International Symposium on Information Processing in Sensor Networks(IPSN' 04),2004.
[70]D.D.Culler and M.Strivastava,"Overview of sensor networks," IEEE Computer Society,vol.37,pp.41-49,2004.
[71]J.R.C.Savarese and K.Langendoen,"Robust positioning algorithm for distributed ad-hoc wireless sensor networks," in Proceedings of the USENIX Annual Technical Conference,2002.
[72]K.Whitehouse and D.Culler,"Calibration as parameter estimation in sensor networks,"in Proceedings of the 1st ACM International Workshop on Wireless Sensor Networks and Applications(WSNA' 02),2002.
[73]N.B.Priyantha,A.K.L.Miu,H.Balakrishnan,and S.J.Teller,"The cricket compass for context-aware mobile applications," in Mobile Computing and Networking,pp.1-14,2001.
[74]D.Niculescu and B.Nath,"Dr based positioning in ad hoc networks," Telecommunication Systems,vol.22,pp.267-280,2003.
[75]R.Nagpal,Shrobe,and Bachrach,"Organizing a global coordinate system from local information on an ad hoc sensor network," in 2nd International Workshop on IPSN,Palo Alto,Apr.2003.
[76]L.Kleinrock and J.Silvester,"Optimum transmisison radii for packet radio networks or why six is a magic number," in Proceedings of the National Telecommunication Conference,1978.
[77]N.C.M.Perkins and B.O' Dea,"Emergent wireless sensor network limitations:a plea for advancement in core technologies," in Proceedings of the 1st IEEE International Conference on Sensors(Sensors' 02),2002.
[78]W.C.Y.Lee,Mobile Communications Engineering.McGraw Hill,1998.
[79]M.D.Yacoub,Foundations of Mobile Radio Engineering.CRC Press,1993.
[80]T.Rappaport,Wireless Communications:Principles and Practice.Prentice Hall,2002.
[81]G.Zhou,T.He,S.Krishnamurthy,and A.Stankovic,"Impact of radio irregularity on wireless sensor networks," in Proceedings of the 2nd international conference on Mobile systems,applications,and services,2004.
[82]D.Ganesan,B.Krishnamachari,A.Woo,D.Culler,D.Estrin,and S.Wicker,"Complex behavior at scale:An experimental study of low-power wireless sensor networks," 2002.
[2]G.O.A.Wayne W.Manges and S.F.Smith,"It' s time for sensors to go wireless,"Sensors Magazine,1999.
[3]"Smart dust,http://www.dust-inc.com."
[4]"The wireless integrated network sensors project(wins),http:/www.janet.ucla.edu/wins."
[5]D.E.L.G.M.H.A.Cerpa,J.Elson and J.Zhao,"Habitat monitoring:application driver for wireless communications technology," in Proceedings of the ACM SIGCOMM Workshop on Data Communications in Latin America and the Caribbean,pp.20-41,2001.
[6]D.C.J.Lundquist and M.Dettinger,"Meteorology and hydrology in yosemite national park:A sensor network application," in Proceedings of the 2nd International Workshop on Information Processing in Sensor Networks(IPSN' 03),pp.518-528,2003.
[7]R.S.D.C.A.Mainwaring,J.Polastre and J.Anderson,"Wireless sensor networks for habitat monitoring," in Proceedings of the 1st ACM International Workshop on Wireless Sensor Networks and Applications(WSNA' 02),pp.88-97,2002.
[8]R.G.C.Intanagonwiwat and D.Estrin,"Directed diffusion:A scalable and robust communication paradigm for sensor networks," in Proceedings of the 6th International Conference on Mobile Computing and Networking(MobiCom' 00),pp.56-66,2000.
[9]R.C.Shah and J.Rabaey,"Energy aware routing for low energy ad hoc sensor networks," in Proceedings of the IEEE Wireless Communications and Networking Conference(WCNC' 02),pp.635-644,2002.
[10]E.D.N.B.Priyantha,H.Balakrishnan and S.Teller,"Anchor-free distributed localization in sensor networks," 2003.
[11]R.G.C.Intanagonwiwat and D.Estrin,"Directed diffusion:A scalable and robust communication paradigm for sensor networks," in Proceedings of the 6th International Conference on Mobile Computing and Networking(MobiCom' 00),pp.56-66,2000.
[12]J.A.Q.Li and D.Rus,"Hierarchical power-routing in sensor networks," in Proceedings of the DIMA CS Workshop on Pervasive Networking,Center for Discrete Mathematics(?)Theoretical Computer Science,2001.
[13]R.Ramanathan and R.Rosales-Hain,"Topology control of multihop wireless networks using transmit power adjustment," in Proceedings of the 19th Joint Conference of the IEEE Computer and Communications Societies(INFOCOM' 00),2000.
[14]J.H.P.Buonodonna and D.Culler,"Active message communication for tiny net- worked sensors," in Proceedings of the 20th Joint Conference of the IEEE Computer and Communications Societies(INFOCOM' 01),2001.
[15]J.H.et al,"System architecture directions for networked sensors," in Proceedings of the 9th International Conference on Architectural Support for Programming Languages and Operating Systems(ASPLOS' 00),2000.
[16]N.A.-G.S.Tilak and W.Heinzelman,"Infrastructure tradeoffs for sensor networks,"in Proceedings of the 1st ACM International Workshop on Wireless Sensor Networks and Applications(WSNA' 02),pp.19-57,2002.
[17]Y.S.I.F.Akyildiz,W.Su,"A survey on sensor networks," IEEE Communications Magazine,vol.40,pp.102-114,2002.
[18]G.J.Pottie and W.J.Kaiser,"Wireless integrated network sensors," Communications of the ACM,vol.43,pp.51-58,2000.
[19]A.C.J.Albowicz and L.Zhang,"Recursive position estimation in sensor networks,"in Proceedings of the 9th International Conference on Network Protocols,pp.35-41,2001.
[20]P.Bergamo and G.Mazzini,"Localization in sensor networks with fading and mobility," in Proceedings of the 13th IEEE International Symposium on Personal,Indoor and Mobile Radio Communications(PIMRC' 02),pp.750-754,2002.
[21]N.Bulusu,J.Heidemann,and D.Estrin,"Gps-less low cost outdoor localization for very small devices," 2000.
[22]N.Bulusu,J.Heidemann,and D.Estrin,"Adaptive beacon placement," in Proceedings of the 21st International Conference on Distributed Computing Systems,pp.489-498,2001.
[23]L.Girod and D.Estrin,"Robust range estimation using acoustic and multimodal sensing," in Proceedi.ngs of the IEEE/RSJ International Conference on Intelligent Robots and Systems(IROS' 01),pp.1312-1320,2001.
[24]J.Heidemann and N.Bulusu,"Using geospatial information in sensor networks,"in Pwceedings of the Workshop on Intersections between Geospatial Information and Information Technology,2001.
[25]R.Iyengar and B.Sikdar,"Scalable and distributed gps free positioning for sensor networks," in Proceedings of the IEEE International Conference on Communications (ICC' 03),pp.338-342,2003.
[26]D.Niculescu and B.Nath,"Ad-hoc positioning system(aps)," in Proc.of IEEE Global Communications Conference(GLOBECOM),pp.2926-2931,2001.
[27]J.R.C.Savarese and J.Beutel,"Locationing in distributed ad-hoc wireless sensor networks," in Proceedings of the International Conference on Acoustics,Speech and Signal Processing(ICASSP' 01),2001.
[28]A.Savvides,C.-C.Han,and M.B.Strivastava,"Dynamic fine-grained localization in ad-hoc networks of sensors," in Mobile Computing and Networking,pp.166-179,2001.
[29]G.P.D.Estrin,L.Girod and M.Srivastava,"Instrumenting the world with wireless sensor networks," in Proceedings of the International Conference on Acoustics,Speech and Signal Processing(ICASSP' 01),2001.
[30]R.H.K.J.M.Kahn and K.S.J.Pister,"Next century challenges:Mobile networking for "smart dust"," in Proceedings of the 5th International Conference on Mobile Computing and Networking(MobiCom' 99),1999.
[31]"Geographical and energy aware routing:a recursive data dissemination protocol for wireless sensor networks," 2001.
[32]H.L.B.Hofmann-Wellenhof and J.Collins,Global Positioning System:Theory and Practice.fourth edition.Springer-Verlag,1997.
[33]Y.Shang and W.Ruml,"Improved rods-based localization," in Proceedings of the 23rd Joint Conference of the IEEE Computer and Communications Societies(INFOCOM'04),2004.
[34]P.Bahl and V.N.Padmanabhan,"RADAR:An -building RF-based user location and tracking system," in Proc.of International Conference of the IEEE Computer and Communications Societies(INFOCOM),pp.775-784,Mar.2000.
[35]G.yao Jin,X.yi Lu,and M.-S.Park,"Spoton:An indoor 3d location sensing technology based on rf signal strength," in Proceedings of the IEEE International Conference on Sensor Networks,Ubiquitous,and Trustworthy Computing(SUTC' 06),2000.
[36]M.P.S.Meguerdichian,F.Koushanfar and M.Srivastava,"Coverage problems in wireless ad-hoc sensor networks," in Proceedings of the 20th Joint Conference of the IEEE Computer and Communications Societies(INFOCOM' 01),2001.
[37]M.H.S.Capkun and J.Hubaux,"Gps-free positioning in mobile ad-hoc networks,"in n Proceedings of the 34th Hawaii International Conference on System Sciences (HICSS' 01),2001.
[38]S.Meguerdichian,S.Slijepcevic,V.Karayan,and M.Potkonjak,"Localized algorithms in wireless ad-hoc networks:location discovery and sensor exposure," in MOBIHOC 2001.
[39]T.He,C.Huang,B.Blum,J.Stankovic,and T.Abdelzaher,"Range-free localization schemes in large scale sensor networks," in MobiCom 2003.,pp.81-95,2003.
[40]M.Sichitiu and V.Ramadurai,"Localization of wireless sensor networks with a mobile beacon," in Proceedings of the 1st IEEE International Conference on Mobile Ad-hoc and Sensor Systems(MASS' 04),pp.174-183,2004.
[41]B.Kusy,A.Ledeczi,M.Maroti,and L.Meertens,"Node-density independent localization,"in Proc.of Information Processing in Sensor Networks(IPSN),2003.
[42]A.Nasipuri and K.Li,"A directionality based location discovery scheme for wireless sensor networks," in Proceedings of the 1st ACM International Workshop on Wire-less Sensor Networks and Applications(WSNA' 02),2002.
[43]P.S.A.W.A.Hatter,A.Hopper and P.Webster,"The anatomy of a contextaware application," in Proceedings of the 5th International Conference on Mobile Computing and Networking(MobiCom' 99),1999.
[44]A.C.N.B.Priyantha and H.Balakrishnan,"The cricket location-support system,"in Proceedings of the 6th International Conference on Mobile Computing and Net-working(MobiCom' 00),2000.
[45]H.P.A.Savvides and M.Srivastava,"The bits and flops of the n-hop multilateration primitive for node localization problems," in Proceedings of the 1st ACM International Workshop on Wireless Sensor Networks and Applications(WSNA' 02),2002.
[46]L.Doherty,K.pister,and L.E.Ghaoui,"Convex position estimation in wireless sensor networks," in Proc.of International Conference of the IEEE Computer and Communications Societies(INFOCOM),pp.1655-1663,Apr.2001.
[47]L.Hu and D.Evans,"Localization for mobile sensor networks," in Proceedings of the 10th annual international conference on Mobile computing and networking.
[48]C.Zhou and B.Krishnamachari,"Localized topology generation mechanisms for self-configuring sensor networks," in Proceedigns of IEEE Global Communications Conference(GLOBECOM' 03),2003.
[49]D.Moore,J.Leonard,D.Rus,and S.Teller,"Robust distributed network localization with noisy range measurements," in Proceedings of the 1st International Conference on Embedded Networked Sensor Systems(SenSys'04),pp.50-61,2004.
[50]S.N.Simic and S.Sastry,"A distributed algorithm for localization in random wireless networks," 2002.
[51]D.D.Culler and M.Strivastava,"Macro-calibration in sensor/actuator networks,"Mobile Networks and Applications,vol.8,pp.463-472,2004.
[52]W.Xu,T.Wood,W.Trappe,and Y.Zhang,"Channel surfing and spatial retreats:defenses against wireless denial of service," in Proceedings of the ACM workshop on Wireless security,pp.80-89,2004.
[53]Y.Hu,A.Perrig,and D.Johnson,"Packet leashes:a defense against wormhole attacks in wireless networks," in INFOCOM 2003,pp.1976-1986,2003.
[54]Z.Li,W.Trappe,Y.Y.Zhang,and B.Nath,"Robust statistical methods for securing wireless localization in sensor networks," in IPSN 2005,pp.91-98,2005.
[55]S.Brands and D.Chaum,"Distance-bounding protocols," in Theory and Application of Cryptographic Techniques,pp.344-359,1993.
[56]N.Sastry,U.Shankar,and D.Wagner,"Secure verification of location claims," in Proceedings of the 2003 ACM workshop on Wireless security,2003.
[57]B.Waters and E.Felten,"Proving the location of tamper resistant devices," 2003.
[58]S.Capkun,L.Buttyan,and J.Hubaux,"Sector:Secure tracking of node encounters in multi-hop wireless networks," in ACM Workshop on Security of Ad Hoc and Sensor Networks(SASN)2003,pp.21-32,2003.
[59]P.Tao,A.Rudys,A.M.Ladd,and D.S.Wallach,"Wireless lan location-sensing for security applications," in Proceedings of the ACM Workshop on Wireless Security,pp.11-20,2003.
[60]E.Gabber and A.Wool,"How to prove where you are:Tracking the location of customer equipment," in A CM Conference on Computer and Communications Security,pp.142-149,1998.
[61]L.Lazos and R.Poovendran,"Serloc:Secure range-independent localization for wireless sensor networks," in Proceedings of the 2004 A CM Workshop on Wireless Security,pp.21-30,2004.
[62]M.G.Kuhn,"An asymmetric security mechanism for navigation signals," in Proceedings of the Information Hiding Workshop,pp.239-252,2004.
[63]D.Liu,P.Ning,and W.Du,"ttack-resistant location estimation in sensor networks,"in IPSN 2005,pp.99-106,2005.
[64]D.S.B.Przydatek and A.Perrig,"Sia:secure information aggregation in sensor networks," in Proceedings of the 1st International Conference on Embedded Networked Sensor Systems(SenSys'03),pp.255-265,2003.
[65]D.Wagner,"Resilient aggregation in sensor networks," in Proceedings of the 2nd ACM workshop on Security of ad hoc and sensor networks(SASN'04),pp.78-87,2004.
[66]K.Langendoen and N.Reijers,"Distributed localization in wireless sensor networks:a quantitative comparison," 2002.
[67]Y.Z.Y.Shang,W.Ruml and M.P.J.Fromherz,"Localization from mere connectivity,"in Proceedings of the 4th acre international symposium on mobile ad hoc networking computing(MobiHoc' 03),pp.201-211,2003.
[68]P.Biswas and Y.Ye,"A distributed method for solving semidefinite programs arising from ad hoc wireless sensor network localization," in Technical report,Dept of Management Science and Engineering,Stanford University,2003.
[69]P.Biswas and Y.Ye,"Semidefinite programming for ad hoc wireless sensor network localization," in Proceedings of the the 4th International Symposium on Information Processing in Sensor Networks(IPSN' 04),2004.
[70]D.D.Culler and M.Strivastava,"Overview of sensor networks," IEEE Computer Society,vol.37,pp.41-49,2004.
[71]J.R.C.Savarese and K.Langendoen,"Robust positioning algorithm for distributed ad-hoc wireless sensor networks," in Proceedings of the USENIX Annual Technical Conference,2002.
[72]K.Whitehouse and D.Culler,"Calibration as parameter estimation in sensor networks,"in Proceedings of the 1st ACM International Workshop on Wireless Sensor Networks and Applications(WSNA' 02),2002.
[73]N.B.Priyantha,A.K.L.Miu,H.Balakrishnan,and S.J.Teller,"The cricket compass for context-aware mobile applications," in Mobile Computing and Networking,pp.1-14,2001.
[74]D.Niculescu and B.Nath,"Dr based positioning in ad hoc networks," Telecommunication Systems,vol.22,pp.267-280,2003.
[75]R.Nagpal,Shrobe,and Bachrach,"Organizing a global coordinate system from local information on an ad hoc sensor network," in 2nd International Workshop on IPSN,Palo Alto,Apr.2003.
[76]L.Kleinrock and J.Silvester,"Optimum transmisison radii for packet radio networks or why six is a magic number," in Proceedings of the National Telecommunication Conference,1978.
[77]N.C.M.Perkins and B.O' Dea,"Emergent wireless sensor network limitations:a plea for advancement in core technologies," in Proceedings of the 1st IEEE International Conference on Sensors(Sensors' 02),2002.
[78]W.C.Y.Lee,Mobile Communications Engineering.McGraw Hill,1998.
[79]M.D.Yacoub,Foundations of Mobile Radio Engineering.CRC Press,1993.
[80]T.Rappaport,Wireless Communications:Principles and Practice.Prentice Hall,2002.
[81]G.Zhou,T.He,S.Krishnamurthy,and A.Stankovic,"Impact of radio irregularity on wireless sensor networks," in Proceedings of the 2nd international conference on Mobile systems,applications,and services,2004.
[82]D.Ganesan,B.Krishnamachari,A.Woo,D.Culler,D.Estrin,and S.Wicker,"Complex behavior at scale:An experimental study of low-power wireless sensor networks," 2002.