A research area that has recently gained great interest is the development of network architectures relating to the tracking of wireless VoIP devices. This is particularly so for architectures based on the popular Session Initiation Protocol (SIP). Previous work, however, in this area does not consider the impact of combined VoIP and tracking on the capacity and call set-up time of the architectures. Previous work also assumes that location information is always available from sources such as GPS, a scenario that rarely is found in practice. The inclusion of multiple positioning systems in tracking architectures has not been hitherto explored. It is the purpose of this thesis to design and test SIP-based architectures that address these key issues. Our first main contribution is the development of a tracking-only SIP based architecture. This architecture is designed for intermittent GPS availability, with wireless network tracking as the back-up positioning technology. Such a combined tracking system is more conducive with deployment in real-world environments. Our second main contribution is the development of SIP based tracking architectures that are specifically aimed at mobile wireless VoIP systems. A key aspect we investigate is the quantification of the capacity constraints imposed on VoIP-tracking architectures. We identify such capacity limits in terms of SIP call setup time and VoIP QoS metrics, and determine these limits through experimental measurement and theoretical analyses. Our third main contribution is the development of a novel SIP based location tracking architecture in which the VoIP application is modified. The key aspect of this architecture is the factor of two increase in capacity that it can accommodate relative to architectures utilizing standard VoIP. An important aspect of all our tracking architectures is the Tracking Server. This server supplies the location information in the event of GPS unavailability. A final contribution of this thesis is the development of novel particle-filter based tracking algorithms that specifically address the GPS intermittency issue. We show how these filters interact with other features of our SIP based architectures in a seamless fashion.

A research area that has recently gained great interest is the development of network architectures relating to the tracking of wireless VoIP devices. This is particularly so for architectures based on the popular Session Initiation Protocol (SIP). Previous work, however, in this area does not consider the impact of combined VoIP and tracking on the capacity and call set-up time of the architectures. Previous work also assumes that location information is always available from sources such as GPS, a scenario that rarely is found in practice. The inclusion of multiple positioning systems in tracking architectures has not been hitherto explored. It is the purpose of this thesis to design and test SIP-based architectures that address these key issues. Our first main contribution is the development of a tracking-only SIP based architecture. This architecture is designed for intermittent GPS availability, with wireless network tracking as the back-up positioning technology. Such a combined tracking system is more conducive with deployment in real-world environments. Our second main contribution is the development of SIP based tracking architectures that are specifically aimed at mobile wireless VoIP systems. A key aspect we investigate is the quantification of the capacity constraints imposed on VoIP-tracking architectures. We identify such capacity limits in terms of SIP call setup time and VoIP QoS metrics, and determine these limits through experimental measurement and theoretical analyses. Our third main contribution is the development of a novel SIP based location tracking architecture in which the VoIP application is modified. The key aspect of this architecture is the factor of two increase in capacity that it can accommodate relative to architectures utilizing standard VoIP. An important aspect of all our tracking architectures is the Tracking Server. This server supplies the location information in the event of GPS unavailability. A final contribution of this thesis is the development of novel particle-filter based tracking algorithms that specifically address the GPS intermittency issue. We show how these filters interact with other features of our SIP based architectures in a seamless fashion.

A general automotive navigation system is a satellite navigation system designed for use inautomobiles. It typically uses GPS to acquire position data to locate the user on a road in the unit's map database. However, due to recent improvements in the performance of small and lightweight micro-machined electromechanical systems (MEMS) inertial sensors have made the application of inertial techniques to such problems, possible. This has resulted in an increased interest in the topic of inertial navigation. In location tracking system, sensors are used either individually or in conjunction like in data fusion. However, still they remain noisy, and so there is a need to measure maximum data and then make an efficient system that can remove the noise from data and provide a better estimate. The task of this thesis work was to take data from two sensors, and use an estimation technique toprovide an accurate estimate of the true location. The proposed sensors were an accelerometer and a GPS device. This thesis however deals with using accelerometer sensor and using estimation scheme, Kalman filter. The thesis report presents an insight to both the proposed sensors and different estimation techniques. Within the scope of the work, the task was performed using simulation software Matlab. Kalman filter’s efficiency was examined using different noise levels.

A general automotive navigation system is a satellite navigation system designed for use in automobiles. It typically uses GPS to acquire position data to locate the user on a road in the unit's map database. However, due to recent improvements in the performance of small and light weight micro-machined electromechanical systems (MEMS) inertial sensors have made the application ofinertial techniques to such problems, possible. This has resulted in an increased interest in the topic of inertial navigation. In location tracking system, sensors are used either individually or in conjunction like in data fusion.However, still they remain noisy, and so there is a need to measure maximum data and then make an efficient system that can remove the noise from data and provide a better estimate.The task of this thesis work was to take data from two sensors, and use an estimation technique to provide an accurate estimate of the true location. The proposed sensors were an accelerometer and aGPS device. This thesis however deals with using accelerometer sensor and using estimation scheme, Kalman filter. This thesis report presents an insight to both the proposed sensors and different estimation techniques.Within the scope of the work, the task was performed using simulation software Matlab. Kalman filter’s efficiency was examined using different noise levels.

No description available.

This study evaluated the potential of using Passive Radiofrequency Identification [RFID] Technology as basis for a Real Time Location Tracking System [RTLTS] to assist an individual with a visual impairment participating in physical activities, such as basketball. While RTLTSs exist based upon other technologies, Passive RFID Technology had yet to be examined for its potential in such an application. In this study, a system was designed and modified, for Passive RFID Technology, in order to enhance the performance of the RTLTS. More specifically, the first iteration of the software code employed the use of multiple RFID antennas to cooperatively designate unique zones, which allowed for the identification of a user’s general position. A series of tests were then conducted to assess the system’s accuracy. In addition, it was determined whether or not factors, such as the addition of multiple tags identifying an object, change in the attenuation level and height level of the antenna, or the position of the tag, had a significant effect on the accuracy of the system. This study showed that the system’s greatest accuracy was obtained when six distinct Passive RFID tags were used to identify the object and when the antenna had a direct line of sight to the tags. Results also showed that these read accuracy rates were indeed comparable to other technologies. Therefore, there exists optimism in using Passive RFID technology as a basis for a RTLTS to assist an individual with a visual impairment.

No description available.

Social networks have been used to understand how information flows through an organization as well as identifying individuals that appear to have control over this information flow. Such individuals are identified as being central nodes in a graph representation of the social network and have high "betweenness" values. Rather than looking at graphs derived from email, on-line forums, or telephone connections, we consider sequences of bipartite graphs that represent face-to-face meetings between individuals, and define a new metric to identify the information elite individuals. We show that, in our simulations, individuals that attend many meetings with many different people do not always have high betweenness values, even though they seem to be the ones that control the information flow. / Singapore-MIT Alliance (SMA)

The presented thesis deals with the subject of tracking via GPS and focuses on possibilities of the practical implementation of user tracking system with the help of mobile end user devices. The introductory theoretical part shortly describes the properties and history of the GPS navigation system. It outlines possible development of end user mobile applications on the level of operating systems and mobile web applications. The final theoretical part provides a short outline of properties of tacking systems available in the Czech market. The primary aim of the thesis was to create an application which would enable the tracking of user position via GPS. The practical part describes the selected solution as well as the individual parts of the designed tracking system. The resulting system allows to record and track user position determined by a mobile phone with an integrated GPS module. The systems also enables the creation of user groups, tracking their routes and visualization of the given position or entire route on a map.

The following paper describes a fall detection and activity monitoring system with position detection based on Zigbee transceivers.The main objective is to reduce the time taken for emergency personnel to respond to falls among the elderly. Especially when the victim is unconscious or delirious, position tracking reduces location determination time within a busy hospital or nursing home environment and facilitates immediate treatment. Reduced response times correlate to decreased morbidity and mortality rates. Background is provided on the major wireless network advances currently deployed in a healthcare setting for asset and personnel tracking, etiology of falls, and several methods of detecting falls using sensors and image processing techniques. Data analysis proves that a precise coordinate tracking system was infeasible using the XBee RF module (based on the Zigbee protocol) due to environmental noise, a poor antenna construction and lack of precise signal strength measurements. A primitive scheme with lower resolution and higher reliability associating a single location with each Zigbee transceiver was employed. A pedometer function was added to the project to monitor the user’s daily activity and to potentially serve as a predictor of falls through the interpretation of mobility and gait patterns related to step counts.