A statistical modeling approach to location estimation. (2002)

by T Roos, P Myllymaki, H Tirri
Venue:IEEE Transactions on Mobile Computing,
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Wireless Sensor Network Localization Techniques

by Guoqiang Mao, Barıs Fidan, Brian D. O. Anderson
"... Wireless sensor network localization is an important area that attracted significant research interest. This interest is expected to grow further with the proliferation of wireless sensor network applications. This paper provides an overview of the measurement techniques in sensor network localizat ..."
Abstract - Cited by 209 (5 self) - Add to MetaCart
Wireless sensor network localization is an important area that attracted significant research interest. This interest is expected to grow further with the proliferation of wireless sensor network applications. This paper provides an overview of the measurement techniques in sensor network localization and the one-hop localization algorithms based on these measurements. A detailed investigation on multihop connectivity-based and distance-based localization algorithms are presented. A list of open research problems in the area of distance-based sensor network localization is provided with discussion on possible approaches to them.

Bayesian indoor positioning systems

by Eiman Elnahrawy, Richard P. Martin, Wen-hua Ju, P. Krishnan, David Madigan - In Infocom , 2005
"... Abstract — In this paper, we introduce a new approach to location estimation where, instead of locating a single client, we simultaneously locate a set of wireless clients. We present a Bayesian hierarchical model for indoor location estimation in wireless networks. We demonstrate that our model ach ..."
Abstract - Cited by 102 (15 self) - Add to MetaCart
Abstract — In this paper, we introduce a new approach to location estimation where, instead of locating a single client, we simultaneously locate a set of wireless clients. We present a Bayesian hierarchical model for indoor location estimation in wireless networks. We demonstrate that our model achieves accuracy that is similar to other published models and algorithms. By harnessing prior knowledge, our model eliminates the requirement for training data as compared with existing approaches, thereby introducing the notion of a fully adaptive zero profiling approach to location estimation. Index Terms — Experimentation with real networks/Testbed, Statistics, WLAN, localization,
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Statistical Learning Theory for Location Fingerprinting in Wireless LANs

by Roberto Battiti, Mauro Brunato, Alessandro Villani , 2002
"... In this paper, techniques and algorithms developed in the framework of statistical learning theory are analyzed and applied to the problem of determining the location of a wireless device by measuring the signal strengths from a set of access points (location fingerprinting). Statistical Learning Th ..."
Abstract - Cited by 95 (4 self) - Add to MetaCart
In this paper, techniques and algorithms developed in the framework of statistical learning theory are analyzed and applied to the problem of determining the location of a wireless device by measuring the signal strengths from a set of access points (location fingerprinting). Statistical Learning Theory provides a rich theoretical basis for the development of models starting from a set of examples. Signal strength measurement is part of the normal operating mode of wireless equipment, in particular Wi-Fi, so that no custom hardware is required. The proposed

A System for LEASE: Location Estimation Assisted by Stationery Emitters for Indoor RF Wireless Networks

by A. S. Krishnakumar, A. S. Krishnakumar, Wen-hua Ju, Colin Mallows, Sachin Ganu - In IEEE Infocom , 2004
"... In this paper, we present LEASE, a new system and framework for Location Estimation Assisted by Stationary Emitters for indoor RF wireless networks. Unlike previous studies, we emphasize the deployment aspect of location estimation engines. Motivated thus, we present an adaptable infrastructure-base ..."
Abstract - Cited by 63 (1 self) - Add to MetaCart
In this paper, we present LEASE, a new system and framework for Location Estimation Assisted by Stationary Emitters for indoor RF wireless networks. Unlike previous studies, we emphasize the deployment aspect of location estimation engines. Motivated thus, we present an adaptable infrastructure-based system that uses a small number of stationary emitters (SEs) and sniffers employed in a novel way to locate standard wireless clients in an enterprise. We present the components of the system and its architecture, and new nonparametric techniques for location estimation that work with a small number of SEs. Our techniques for location estimation can also be used in a client-based deployment. We present experimental results of using our techniques at two sites demonstrating the ability to perform location estimation with good accuracy in our new adaptable framework.
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RightSPOT: A Novel Sense of Location for a Smart Personal Object

by John Krumm, Gerry Cermak, Eric Horvitz - Proc. of UBICOMP 2003. Volume LNCS 2864., Springer-Verlag (2003 , 2003
"... Abstract. One of the main prerequisites for location-based services is knowledge of location. We present a simple algorithm for computing the location of a device based on signal strengths from FM radio stations. The motivation for this method comes from a new class of smart personal objects that wi ..."
Abstract - Cited by 55 (6 self) - Add to MetaCart
Abstract. One of the main prerequisites for location-based services is knowledge of location. We present a simple algorithm for computing the location of a device based on signal strengths from FM radio stations. The motivation for this method comes from a new class of smart personal objects that will receive digital data encoded in regular FM radio broadcasts. Given their built-in ability to receive FM and to measure signal strengths, we show how to exploit this ability to measure the device’s location. Our algorithm, called RightSPOT, is designed to be robust to manufacturing variations among devices that affect how they measure signal strength. Toward this end, we present a location classification algorithm based not on absolute signal strengths, but on a ranking of signal strengths from multiple FM radio stations. In tests with three devices in six suburban areas, we show that we can correctly infer the device’s location about 80 % of the time. 1
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Network-based wireless location

by Ali H. Sayed, Alireza Tarighat - IEEE Signal Process. Mag , 2005
"... [Challenges faced in developing techniques for accurate wireless location information] Wireless location refers to the geographic coordinates of a mobile subscriber in cellular or wireless local area network (WLAN) environments. Wireless location finding has emerged as an essential public safety fea ..."
Abstract - Cited by 54 (1 self) - Add to MetaCart
[Challenges faced in developing techniques for accurate wireless location information] Wireless location refers to the geographic coordinates of a mobile subscriber in cellular or wireless local area network (WLAN) environments. Wireless location finding has emerged as an essential public safety feature of cellular systems in response to an order issued by the Federal Communications Commission (FCC) in 1996. The order mandated all wireless service providers to deliver accurate location information of an emergency 911 (E-911) caller to public safety answering points (PSAPs). The FCC mandate aims to solve a serious public safety problem caused by the fact that, at present, a large proportion of all 911 calls originate from mobile phones, the location of which cannot be determined with existing technology. However, many difficulties intrinsic to the wireless environment make meeting the FCC objective challenging; these challenges include channel fading, low signal-to-noise ratios (SNRs), multiuser interference, and multipath conditions. In addition to emergency services, there are many other applications for wireless location technology, including monitoring and tracking for security reasons, location sensitive

A practical approach to landmark deployment for indoor localization

by Yingying Chen, John-austen Francisco, Richard P. Martin - in Proceedings of the Third Annual IEEE Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks (SECON , 2006
"... Abstract — We investigate the impact of landmark placement on localization performance using a combination of analytic and experimental analysis. For our analysis, we have derived an upper bound for the localization error of the linear least squares algorithm. This bound reflects the placement of la ..."
Abstract - Cited by 53 (26 self) - Add to MetaCart
Abstract — We investigate the impact of landmark placement on localization performance using a combination of analytic and experimental analysis. For our analysis, we have derived an upper bound for the localization error of the linear least squares algorithm. This bound reflects the placement of landmarks as well as measurement errors at the landmarks. We next develop a novel algorithm, maxL−minE, that using our analysis, finds a pattern for landmark placement that minimizes the maximum localization error. To show our results are applicable to a variety of localization algorithms, we then conducted a series of localization experiments using both an 802.11 (WiFi) network as well as an 802.15.4 (ZigBee) network in a real building environment. We use both Received Signal Strength (RSS) and Time-of-Arrival (ToA) as ranging modalities. Our experimental results show that our landmark placement algorithm is generic because the resulting placements improve localization performance across a diverse set of algorithms, networks, and ranging modalities. I.
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Advanced Integration of WiFi and Inertial Navigation Systems for Indoor Mobile Positioning

by F. Evennou, F. Marx , 2006
"... This paper presents an aided dead-reckoning navigation structure and signal processing algorithms for self localization of an autonomous mobile device by fusing pedestrian dead reckoning and WiFi signal strength measurements. WiFi and inertial navi-ation systems (INS) are used for positioning and at ..."
Abstract - Cited by 45 (0 self) - Add to MetaCart
This paper presents an aided dead-reckoning navigation structure and signal processing algorithms for self localization of an autonomous mobile device by fusing pedestrian dead reckoning and WiFi signal strength measurements. WiFi and inertial navi-ation systems (INS) are used for positioning and attitude determination in a wide range of applications. Over the last few years, a number of low-cost inertial sensors have become available. Although they exhibit large errors, WiFi measurements can be used to correct the drift weakening the navigation based on this technology. On the other hand, INS sensors can interact with the WiFi positioning system as they provide high-accuracy real-time navigation. A structure based on a Kalman filter and a particle filter is proposed. It fuses the heterogeneous information coming from those two independent technologies. Finally, the benefits of the proposed architecture are evaluated and compared with the pure WiFi and INS positioning systems.

A.: An empirical characterization of radio signal strength variability in 3-d ieee 802.15.4 networks using monopole antennas

by Dimitrios Lymberopoulos, Quentin Lindsey, Andreas Savvides , 2006
"... Abstract. The wide availability of radio signal strength attenuation information on wireless radios has received considerable attention as a convenient means of deriving positioning information. Although some schemes have been shown to work in some scenarios, many agree that the robustness of such s ..."
Abstract - Cited by 38 (0 self) - Add to MetaCart
Abstract. The wide availability of radio signal strength attenuation information on wireless radios has received considerable attention as a convenient means of deriving positioning information. Although some schemes have been shown to work in some scenarios, many agree that the robustness of such schemes can be easily compromised when low power IEEE 802.15.4 radios are used. Leveraging a recently installed sensor network testbed, we provide a detailed characterization of signal strength properties and link asymmetries for the CC2420 IEEE 802.15.4 compliant radio using a monopole antenna. To quantify the several factors of signal unpredictability due to the hardware, we have collected several thousands of measurements to study the antenna orientation and calibration effects. Our results show that the often overlooked antenna orientation effects are the dominant factor of the signal strength sensitivity, especially in the case of 3-D network deployments. This suggests that the antenna effects need to be carefully considered in signal strength schemes. 1
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Handling Samples Correlation in the Horus System

by Moustafa Youssef, Ashok Agrawala , 2003
"... We present an autoregressive model for modeling samples autocorrelation from the same access point in WLAN location determination systems. Our work is in the context of the Horus system, which is a probabilistic WLAN location determination system. We show that the autocorrelation between consecutive ..."
Abstract - Cited by 36 (4 self) - Add to MetaCart
We present an autoregressive model for modeling samples autocorrelation from the same access point in WLAN location determination systems. Our work is in the context of the Horus system, which is a probabilistic WLAN location determination system. We show that the autocorrelation between consecutive samples from the same access point can be as high as 0.9. Using our model, we describe a technique to use multiple signal strength samples from each access point, taking the high autocorrelation into account, to achieve better accuracy. Implementation of the technique in the Horus system shows that the average system accuracy is increased by more than 50%. Our results show that assuming independence of samples from the same access point can lead to degraded performance as the number of samples used in the estimation algorithm is increased, due to the wrong independence assumption. We also discuss how to incorporate the new technique with other algorithms for enhancing the performance of WLAN location determination systems.
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