Development of network planning techniques for wireless indoor positioning systems

ได้ทุนอุดหนุนการวิจัยจากมหาวิทยาลัยเทคโนโลยีสุรนารี ปีงบประมาณ 255

Development of hybrid techniques for wireless indoor positioning systems in multiple-floor building

ได้ทุนอุดหนุนการวิจัยจากมหาวิทยาลัยเทคโนโลยีสุรนารี ปีงบประมาณ พ.ศ.255

Taxonomy of fundamental concepts of localization in cyber-physical and sensor networks

Localization is a fundamental task in Cyber-Physical Systems (CPS), where data is tightly coupled with the environment and the location where it is generated. The research literature on localization has reached a critical mass, and several surveys have also emerged. This review paper contributes on the state-of-the-art with the proposal of a new and holistic taxonomy of the fundamental concepts of localization in CPS, based on a comprehensive analysis of previous research works and surveys. The main objective is to pave the way towards a deep understanding of the main localization techniques, and unify their descriptions. Furthermore, this review paper provides a complete overview on the most relevant localization and geolocation techniques. Also, we present the most important metrics for measuring the accuracy of localization approaches, which is meant to be the gap between the real location and its estimate. Finally, we present open issues and research challenges pertaining to localization. We believe that this review paper will represent an important and complete reference of localization techniques in CPS for researchers and practitioners and will provide them with an added value as compared to previous surveys

Urban, suburban and rural channel models based on cellular and wireless area network signals for positioning purposes

Location information is becoming more and more useful in everyday life. The cellular- based and wireless area network based positioning are being used to predict the location of users in environments such as indoors and densely urban, where the Global Navigation Satellite Systems often fail. The Received Signal Strength (RSS) is used more and more due to its wide availability on any mobile device and based on various signals. However, studies about the availability of signal measurements in various urban and sub-urban scenarios and about the RSS fluctuations in various terrain types are still lacking in the current literature. The main objective of this thesis is to analyze method wide range of measurement-based RSS in urban, suburban and rural environments. The thesis is divided in two parts. In the literature study part, issues related to cellular and wireless local area networks (WLANs) such as frequency bands, system architectures, radio interfaces and RSS measurements are described. Also the propagation channel characteristics and the different path-loss models existing in the literature are exposed. The information explained in this part was useful in order to be able to process the available data measurements. In the measurements and analysis part, the collected results were evaluated. The different parameters of cellular and WLAN signals were studied and compared. Availability of signals in various scenarios, density of the transmitters and path loss coefficients were deeply analyzed, by dividing the measured scenarios into seven distinct environments: airport areas, Seaside or beach areas, Mountain or forest areas, suburban areas, densely urban areas, lake areas, and other urban areas. The obtained results provide more insight into the availability of RSS signal measurements on mobile devices nowadays and into the possibility of creating generic and unified RSS-based positioning algorithms (based on the similarities between different types of signals and different types of environments)

Calibrating RSS-based Indoor Positioning Systems

Location estimation based on Received Signal Strength (RSS) is the prevalent method in indoor positioning. For RSS-based methods a massive collection of training RSS samples is needed to calibrate the positioning system and to achieve a high positioning quality. The quality of these methods is directly related to the placement of the wireless sensors in the workspace and the Radio Map used to compute the user location. Traditionally deploying the reference points and building the Radio Map require human intervention and are extremely time-consuming. In this paper we aim to reduce these manual calibration efforts. We propose an automatic approach both to build a Radio Map in the given environment and to assess the best system calibration that fits the required positioning quality. The approach has been tested on the most used radio frequency-based technologies, i.e., IEEE 802.11 and Bluetoot