The effectiveness of location aware applications is dependent on the accuracy of the supporting positioning system. This work evaluates the accuracy of an indoors 802.11 positioning system based on signal strength fingerprinting. The system relies on an empirical survey of signal strength prior to positioning. During this survey, signal strength recordings are made at a set of positions across the environment. These recordings are used as training data for the system during positioning. In this thesis, two surveying methods, five positioning algorithms, and two spatial output averaging methods are trialled. Accuracy is determined by empirical testing in two separate environments: a 100m square domestic house and the 1,333m square third floor of the University of New South Wales Computer Science and Engineering building. In the two environments, the lowest mean distance errors are 1.25m and 2.86m respectively.

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 49-50). Also available on the World Wide Web.

Thesis(M.S.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.63-67).

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 63-66). Also available in electronic version. Access restricted to campus users.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 108-112). Also available in electronic version. Access restricted to campus users.

Thesis (M.S. in Computer Science)--Naval Postgraduate School, Sept. 2004. / Thesis advisor(s): Gurminder Singh, Alex Bordetsky. Includes bibliographical references (p. 73). Also available online.

The most important standard in wireless local area networks (WLANs) is IEEE 802.11. For this reason, much of the research work for the enhancement of WLANs is generally based on the behaviour of the IEEE 802.11 standard. This standard is divided into several layers. One of the important layers is the medium access control (MAC) layer. It plays an important role in accessing the transmission medium and data transmission of wireless stations. However, it still presents many challenges related to the performance metrics of quality of service (QoS), such as system throughput and access delay. Modelling and performance analysis of the MAC layer are also extremely important. Thus, the performance modelling and analysis have become very important in the design and enhancement of wireless networks. Therefore, this research work is devoted to evaluate and enhance the performance modelling of IEEE 802.11 MAC-distributed coordination function (DCF), which can lead to the improvement of the performance metrics of QoS. In order to more accurately evaluate the system performance for IEEE 802.11 DCF, a new analytical model to compute a packet transmission probability for IEEE 802.11 DCF has been proposed based on difference probabilities in transmission mechanism. The performance saturated throughput is then evaluated with the proposed analytical model. In addition, a new analytical model for estimating the MAC layer packet delay distribution of IEEE 802.11 DCF is also proposed. The performance results highlight the importance of considering the different probabilities between events in transmission mechanism for an accurate performance evaluation model of IEEE 802.11 DCF in terms of throughput and delay. To enhance the effectiveness of IEEE 802.11 DCF, a new dynamic control backoff time algorithm to enhance both the delay and throughput performances of the IEEE 802.11 DCF is proposed. This algorithm considers the distinction between high and low traffic loads in order to deal with unsaturated traffic load conditions. In particular, the equilibrium point analysis (EPA) model is used to represent the algorithm under various traffic load conditions. Results of extensive simulation experiments illustrate that the proposed algorithm yields better performance throughput and a better average transmission packet delay than related algorithms.

This master's thesis deals with security of wireless network standard 802.11. There are described security mechanisms as hide SSID, MAC address filtering, WEP, WPA, WPA2 protocols. There are described also the most often kinds of attacks (Denial of Service, disclosure WEP key, Man-in-the-Middle). The work contains investigation of used security mechanisms in wireless networks in parts of Brno. There were used NetStumbler and inSSIDer applications for this measurement. The last part of work contains measurement of security mechanisms (WEP, WPA, WPA2) effect to transfer rate from the point of view of the end user. The measurement was realized with Iperf application.

The Master´s thesis „Traffic management in wireless networks“ discusses how to ensure Quality of Service in these networks. A term „traffic management“ is connected mainly with certain restrictions and prioritization of some services and traffics in network. The thesis contains an overview of the most used wireless technologies and describes the approach of these technologies to ensure QoS. Theoretical part of the thesis follows with the definition of general principles of traffic management in IP networks and provides an overview of network parameters used in evaluating the quality of different types of communications services. Practical part is focused on the most widely used wireless technology of standard 802.11 and also on implementation of remote administration system on a small SOHO routers. These systems allow the use of queueing disciplines to manage QoS. Designed and implemented HTB discipline is tested on a real traffic network model.

This term project analyzes the security of 802.1X based wireless networks and presents the methodology for auditing these networks. The thesis describes various methods of the EAP authentication protocol used in wireless networks, security risks arising from their usage and recommendations for mitigating these risks. The paper also includes implementation of applications for 802.1X based wireless network audit focusing on the EAP protocol processing.