WiFiPoz -- an accurate indoor positioning system

Location based services are becoming an important part of life. Wide adoption of GPS in mobile devices combined with cellular networks has practically solved the problem of outdoor localization needs. The problem of locating an indoor user has being studied only recently. Much research contributed to the innovative concept of an indoor positioning system. By analyzing different technologies and algorithms, this thesis concluded that, considering a trade-off between accuracy and cost, a Wi-Fi based Fingerprint method is proved to be the most promising approach to determine the location of a mobile device. However, the Fingerprint method works in two phases-an offline training phase (collection of Received Signal Strength signatures) and an online phase in which data from the first phase is used to determine the current position of a mobile user. The number of training points in a certain area has a direct impact on the accuracy of the system. As a result, the offline phase is a tedious and cumbersome process and the positioning systems are only as accurate as the offline training phase has been detailed. Moreover, the offline phase must be repeated every time a change in the environment occurs. To avoid these limitations, we focus on improving the accuracy of the indoor positioning system, without increasing the number of training points. This thesis presents a Wi-Fi based system for locating a user inside a building. The system is named WiFiPoz, which means Wi-Fi positioning system based on the zoning method. WiFiPoz has a novel approach to Fingerprint method that incorporates Propagation and zoning methods. Experimental results show that WiFiPoz is highly efficient both in accuracy and costs. Compared to traditional Fingerprint methods, with the optimization of the accuracy of the location estimation, WiFiPoz reduces the number of training points. This feature makes it possible to quickly adapt to changes in the environment. In order to explore another possible solution, this thesis also developed, implemented and tested an indoor positioning system named GIS (Geometric Information based positioning System), which is based on a model proposed by another researcher. Several experiments were run in the offline phase and results were compared between the traditional Fingerprint method, GIS and proposed WiFiPoz. We concluded that WiFiPoz is a more efficient and simple way to increase the accuracy of the location determination with fewer training points --Document

Air Force Institute of Technology Research Report 2004

This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, and Engineering Physics

Context-aware routing system in an indoor scenario

The main aim of this report is to develop, design and analyse a system to simulate a context-aware routing algorithm in an indoor scenario. The context-aware purpose of this project is to take advantage of the interaction of the routing system with an entity when it is relevant. From all the context entities, the spatial environment is one of the most important, and the one which more information can be taken advantage of. Benefits can be obtained from using context-awareness in many ways, which have a special interest in the Information Technologies area. The intention of this report is to create a new application using context information related to the space, to be more precise, the position of the entities within a concrete location, and its preferences. The primary target is to design a supermarket in which benefits can be obtained from the position of the customers, their preferences (concretely the shopping list) and also the location of the products, to create an intelligent and efficient supermarket for the customer (but also for the supermarket in itself) point of view. Knowing the position of the customers and the location of the products in the supermarket can be useful to draw up efficient routes that can guide the customers through the corridors to buy their products quickly, which is the main reason why the system uses a shortest path routing algorithm to find the best route from the customer to the wished product. This algorithm considers the shortest distance and also the position of the rest of the customers so the system is able to guide the customers through another path in cases where they reach congested zones in the supermarket. Bluetooth wireless technology is used to accomplish the localization and system communication task. In addition the routing algorithm is adapted to fit the requirements of the intelligent supermarket. The design and implementation of a GUI simulator written in Java that represents the designed system is the main goal of this project. This simulator serves as a tool to test the system operation offering the possibility to modify parameters such as the rate and distribution type of the arrival of customers, the number of customers, subjective criteria of congestion and speed of the simulation among other parameters. Different types of statistics and the possibility to generate files with the information of the simulation are the main outcomes of this project, besides the GUI. In addition, this information can be translated into a Matlab script using a parser designed for this purpose. Finally the results and conclusions of the system are presented, and the future lines to follow the development of this innovative project

Device Discovery in Frequency Hopping Wireless Ad Hoc Networks

This research develops a method for efficient discovery of wireless devices for a frequency hopping spread spectrum, synchronous, ad hoc network comprised of clustered sub-networks. The Bluetooth wireless protocol serves as the reference protocol. The development of a discovery, or outreach, method for scatternets requires the characterization of performance metrics of Bluetooth piconets, many of which are unavailable in literature. Precise analytical models characterizing the interference caused to Bluetooth network traffic by inquiring devices, the probability mass function of packet error rates between arbitrary pairs of Bluetooth networks, and Bluetooth discovery time distribution are developed. Based on the characterized performance metrics, three scatternet outreach methods are developed and compared. Outreach methods which actively inquire on a regular basis, as proposed in literature, are shown to produce lower goodput, have greater mean packet delay, require more power, and cause significant delays in discovery. By passively remaining available for outreach, each of these disadvantages is avoided

A specification-compatible bluetooth inquiry simplification

We identify and analyze a specification-compatible method for implementing the Bluetooth inquiry function that simplifies the design while reducing the mean inquiry time. Using simulation data and independent empirical measurements, we verify a previously derived probability density function for the inquiry time of a Bluetooth device. Although the derived density matches the simulated data, it does not closely match the measured data. Assuming the manufacturer made a logical simplification to the specification, we derive the probability density function using the simplification and show it matches the empirical data. In addition to simplifying the inquiry substate implementation, the inquiry modification performs better than the specified inquiry process. We also present a simple method to mitigate a noisy channel