Localization in mobile wireless and sensor networks

Many applications in wireless sensor networks require sensor nodes to obtain their absolute geographical positions. There are various localization algorithms have been recently proposed. Localization – finding the position of individual sensor nodes-remains one of the most difficult research challenges. Many applications based on networked sensors require location awareness; a node must be able to find its location.This paper presents a reviewof some localization algorithms which used different techniques such as CAB, GRAHAM’S SCAN, QUERY MODEL, EVENT TRIGGERED DISTRIBUTED OPTIMIZATION, and BILATERATION.

2012 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2012

We consider the problem of sensor localization in a wireless network in a multipath environment, where time and angle of arrival information are available at each sensor. We propose a distributed algorithm based on belief propagation, which allows sensors to cooperatively self-localize with respect to one single anchor in a multihop network. The algorithm has low overhead and is scalable. Simulations show that although the network is loopy, the proposed algorithm converges, and achieves good localization accuracy.

2006

Recently, node localization for multi-hop sensor networks has attracted considerable attention. In these networks, error propagation provides a serious challenge to algorithm development and accuracy of final location estimates. In this paper we introduce a novel computationally efficient distributed algorithm, Cooperative Localization with Optimum Quality of Estimate (CLOQ) which takes advantage of the behavior of the channel to provide accurate indoor positioning. This algorithm uses the quality of ranging and positioning estimates to provide practical and accurate results and more importantly reduce error propagation substantially. Using UWB measurements and modeling of the ranging error in a typical office building we compare the performance of this cooperative localization algorithm with a non-channel based algorithm for indoor ad-hoc sensor environments.

Applied Sciences, 2020

Remarkable progress in radio frequency and micro-electro-mechanical systems integrated circuit design over the last two decades has enabled the use of wireless sensor networks with thousands of nodes. It is foreseen that the fifth generation of networks will provide significantly higher bandwidth and faster data rates with potential for interconnecting myriads of heterogeneous devices (sensors, agents, users, machines, and vehicles) into a single network (of nodes), under the notion of Internet of Things. The ability to accurately determine the physical location of each node (stationary or moving) will permit rapid development of new services and enhancement of the entire system. In outdoor environments, this could be achieved by employing global navigation satellite system (GNSS) which offers a worldwide service coverage with good accuracy. However, installing a GNSS receiver on each device in a network with thousands of nodes would be very expensive in addition to energy constraints. Besides, in indoor or obstructed environments (e.g., dense urban areas, forests, and canyons) the functionality of GNSS is limited to non-existing, and alternative methods have to be adopted. Many of the existing alternative solutions are centralized, meaning that there is a sink in the network that gathers all information and executes all required computations. This approach quickly becomes cumbersome as the number of nodes in the network grows, creating bottle-necks near the sink and high computational burden. Therefore, more effective approaches are needed. As such, this work presents a survey (from a signal processing perspective) of existing distributed solutions, amalgamating two radio measurements, received signal strength (RSS) and angle of arrival (AOA), which seem to have a promising partnership. The present article illustrates the theory and offers an overview of existing RSS-AOA distributed solutions, as well as their analysis from both localization accuracy and computational complexity points of view. Finally, the article identifies potential directions for future research.

Wireless Communications and Mobile Computing, 2012

This paper addresses the problem of localization in sensor networks where, initially, a certain number of sensors are aware of their positions (either by using GPS or by being hand-placed) and are referred to as anchors. Our goal is to localize all sensors with high accuracy, while using a limited number of anchors. Sensors can be equipped with different technologies for signal and angle measurements. These measures can be altered by some errors because of the network environment that induces position inaccuracies. In this paper, we propose a family (AT-Family) of three new distributed localization techniques in wireless sensor networks: free-measurement (AT-Free) where sensors have no capability of measure, signalmeasurement (AT-Dist) where sensors can calculate distances, and angle-measurement (AT-Angle) where sensors can calculate angles. These methods determine the position of each sensor while indicating the accuracy of its position. They have two important properties: first, a sensor node can deduce if its estimated position is close to its real position and contribute to the positioning of others nodes; second, a sensor can eliminate wrong information received about its position. This last property allows to manage measure errors that are the main drawback of measure-based methods such as AT-Dist and AT-Angle techniques. By varying the density and the error rate, simulations show that the three proposed techniques achieve good performances in term of high accuracy of localized nodes and less energy consuming while assuming presence of measure errors and considering low number of anchors.

Computing Research Repository - CORR, 2010

This paper considers N mobile nodes that move together in the vicinity of each other, whose initial poses as well as subsequent movements must be accurately tracked in real time with the assist of M(>=3) reference nodes. By engaging the neighboring mobile nodes in a simple but effective cooperation, and by exploiting both the time-of-arrival (TOA) information (between mobile nodes and reference nodes) and the received-signal-strength (RSS) information (between mobile nodes), an effective new localization strategy, termed cooperative TOA and RSS (COTAR), is developed. An optimal maximum likelihood detector is first formulated, followed by the derivation of a low-complexity iterative approach that can practically achieve the Cramer-Rao lower bound. Instead of using simplified channel models as in many previous studies, a sophisticated and realistic channel model is used, which can effectively account for the critical fact that the direct path is not necessarily the strongest path. ...

Mobile Ad-Hoc Networks: Applications, 2011

2008

In this paper, we propose a range-free cooperative localization algorithm for mobile sensor networks by combining hop distance measurements and particle filtering. In the hop distance measurement step, a differential error correction scheme is devised to reduce the positioning error accumulated over multiple hops. A backoff-based broadcast mechanism is also introduced in our localization algorithm. It efficiently suppresses redundant broadcasts and reduces message overhead. The proposed localization method has fast converges with small location estimation error. We verify our algorithm in various scenarios and compare it with conventional localization methods. Simulation results show that our proposal is superior to the state-of-the-art localization algorithms for mobile sensor networks.

GLOBECOM 2009 - 2009 IEEE Global Telecommunications Conference, 2009

The combination of wideband transmission and cooperative techniques enables high-precision location-awareness. Wideband transmission provides fine delay resolution and multipath resolvability, while cooperation among nodes can yield significant performance benefit in harsh or infrastructure-limited environments. In this paper, we propose to exploit the geometric relationship inherent in multipath propagation, i.e., multipath geometry, via cooperation among nodes for localization. We characterize the contribution of this multipath geometry in terms of the nodes' squared position error bound, which is the fundamental limit of localization accuracy. Analytical and numerical results validate the benefit of using multipath geometry in wideband cooperative localization.

Proceedings of the 3rd international conference on Embedded networked sensor systems - SenSys '05, 2005

The problem of localization of wireless sensor nodes has long been regarded as very difficult to solve, when considering the realities of real world environments. In this paper, we formally describe, design, implement and evaluate a novel localization system, called Spotlight. Our system uses the spatio-temporal properties of well controlled events in the network (e.g., light), to obtain the locations of sensor nodes. We demonstrate that a high accuracy in localization can be achieved without the aid of expensive hardware on the sensor nodes, as required by other localization systems. We evaluate the performance of our system in deployments of Mica2 and XSM motes. Through performance evaluations of a real system deployed outdoors, we obtain a 20cm localization error. A sensor network, with any number of nodes, deployed in a 2500m 2 area, can be localized in under 10 minutes, using a device that costs less than $1000. To the best of our knowledge, this is the first report of a sub-meter localization error, obtained in an outdoor environment, without equipping the wireless sensor nodes with specialized ranging hardware.