Range Free Localization Techniques in Wireless Sensor Networks: A Review

AbstractRecent developments in micro electro mechanical systems (MEMS) technology and wireless communication have propelled the growing applications of wireless sensor networks (WSNs). Wireless sensor network is comprised of large number of small and cheap devices known as sensors. One of the important functions of sensor network is collection and forwarding of data. In most of the applications, it is of much interest to find out the location of the data. This type of information can be obtained by use of localization techniques. So node localization is very crucial to find out the position of node with the help of localization algorithms. Hence, node localization becomes one of the fundamental challenges in WSNs. We make the rigorous reviews on different schemes of localization in sensor networks. On the basis of range measurements, the localization schemes can be broadly classified in two categories such as: range based and range free schemes. The cost and hardware limitation on sensing node preclude the use of range based localization schemes. In most of the sensor network application coarse accuracy is sufficient so range free localization schemes are considered as a substitute to range based schemes. In this paper, the detailed study has been carried out to understand and select the best range free localization algorithm for WSNs. At the end some issues are discussed for future research in the area of localization techniques for WSNs

A hybrid localization approach in 3D wireless sensor network

Location information acquisition is crucial for many wireless sensor network (WSN) applications. While existing localization approaches mainly focus on 2D plane, the emerging 3D localization brings WSNs closer to reality with much enhanced accuracy. Two types of 3D localization algorithms are mainly used in localization application: the range-based localization and the range-free localization. The range-based localization algorithm has strict requirements on hardware and therefore is costly to implement in practice. The range-free localization algorithm reduces the hardware cost but at the expense of low localization accuracy. On addressing the shortage of both algorithms, in this paper, we develop a novel hybrid localization scheme, which utilizes the range-based attribute RSSI and the range-free attribute hopsize, to achieve accurate yet low-cost 3D localization. As anchor node deployment strategy plays an important role in improving the localization accuracy, an anchor node configuration scheme is also developed in this work by utilizing the MIS (maximal independent set) of a network. With proper anchor node configuration and propagation model selection, using simulations, we show that our proposed algorithm improves the localization accuracy by 38.9% compared with 3D DV-HOP and 52.7% compared with 3D centroid

Localización de nodos dentro de una red inalámbrica de sensores

Este proyecto consiste en la implementación de un algoritmo de localización de nodos dentro de una red inalámbrica de sensores (WSN). Para ello hemos desarrollado unas rutinas en NesC utilizando el sistema operativo TinyOS orientado a redes de sensores WSN. La técnica de localización empleada se denomina DV hop y permite localizar un nodo desconocido por medio del numero de saltos de un mensaje enviado a la red de sensores donde se han empleado nodos repetidores de primer nivel y nodos repetidores de segundo nivel. El hardware utilizado son los nodos sensores denominados motas que trabajan bajo la el estándar IEEE802.15.4 y además disponen de una interfaz USB, que a través de ella pueden ser conectados a un ordenador para ser configurados o para poder visualizar los datos recibidos en un hiperterminal de Linux o Windows. Este proyecto lo hemos dividido en tres capítulos bastante bien diferenciados. En primer lugar se hará una introducción de una serie de conceptos teóricos relacionados con las redes WSN tales como sus características principales, utilidades, dispositivos que se utilizan, y las principales técnicas de localización de nodos, centrándonos en el algoritmo DV hop utilizado en la implementación practica de nuestra WSN Posteriormente, se explicará el funcionamiento de cada una de las aplicaciones desarrolladas mediante diagramas de flujo y configuraciones realizadas y como han sido preparadas para su correcto funcionamiento. Por ultimo, una vez implementadas las aplicaciones necesarias, a partir de dos escenarios propuestos para comprobar su funcionamiento, se mostrarán los resultados obtenidos en las pruebas realizadas

Photovoltaics and Electrification in Agriculture

Integration of photovoltaics and electrification in agriculture. Works on the integration of photovoltaics in agriculture, as well as electrification and microgrids in agriculture. In addition, some works on sustainability in agriculture are added

Ressourcenarme und dezentrale Lokalisierung autonomer Sensorknoten in Sensornetzwerken

Diese Dissertation behandelt Distanz- und Lokalisierungsverfahren in ressourcenarmen Sensornetzwerken. Den Kern der Arbeit bildet die ressourcenarme Lokalisierung von Sensorknoten. In Sensornetzwerken mit geringen Genauigkeitsanforderungen kann die einfache Schwerpunktbestimmung (CL) als Lokalisierungsverfahren eingesetzt werden. In den Randgebieten eines Netzwerkes erreicht der CL-Algorithmus jedoch nur eine sehr geringe Genauigkeit. Das neu vorgestellte Verfahren Centroid Localization with Edge Correction (CLwEC) reduziert diesen Lokalisierungsfehler bei geringfügig höherem Ressourcenaufwand deutlich. Eine weitere Verbesserung der Lokalisierung wird durch ein gewichtete Schwerpunktverfahren (WCL) erreicht.This thesis describes algorithms to determine distances and positions in resource-constrained sensor networks. In sensor networks with low accuracy requirements, node’s positions can be calculated by the centroid localization algorithm (CL) provided that all reference nodes can be configured optimal regarding the presented method. In borderlands of a sensor network, the accuracy of the centroid localization decreases enormously. The new presented algorithm centroid localization with edge correction (CLwEC) reduces this positioning error significantly and requires, in comparison the CL, only slightly increased resources. A further improvement of the positioning error was achieved by the new introduced weighted centroid localization algorithm (WCL)

Building Evacuation with Mobile Devices

In der Dissertation wird ein Konzept für ein Gebäudeevakuierungssystem vorgestellt, das es ermöglicht, Personen mit Hilfe mobiler Endgeräte im Evakuierungsfall aus einem Gebäude zu führen. Die Dissertation gliedert sich in drei thematische Bereiche, in denen zunächst ein Konzept für die Systemarchitektur vorgestellt wird und anschließend verschiedene Algorithmen zur Routenplanung sowie zur Lokalisierung der Geräte vorgestellt und evaluiert werden