As wireless devices become more common, the ability to position a wireless device has become a topic of importance. Accurate positioning through technologies such as the Global Positioning System is possible for outdoor environments. Indoor environments pose a different challenge, and research continues to position users indoors. Due to the prevalence of wireless local area networks (WLANs) in many indoor spaces, it is prudent to determine their capabilities for the purposes of positioning. Signal strength and time based positioning systems have been studied for WLANs. Direction or angle of arrival (AOA) based positioning will be possible with multiple antenna arrays, such as those included with upcoming devices based on the IEEE 802.11n standard. The potential performance of such a system is evaluated. The positioning performance of such a system depends on the accuracy of the AOA estimation as well as the positioning algorithm. Two different maximum-likelihood (ML) derived algorithms are used to determine the AOA of the mobile user: a specialized simple ML algorithm, and the space- alternating generalized expectation-maximization (SAGE) channel parameter estimation algorithm. The algorithms are used to determine the error in estimating AOAs through the use of real wireless signals captured in an indoor office environment. The statistics of the AOA error are used in a positioning simulation to predict the positioning performance. A least squares (LS) technique as well as the popular extended Kalman filter (EKF) are used to combine the AOAs to determine position. The position simulation shows that AOA- based positioning using WLANs indoors has the potential to position a wireless user with an accuracy of about 2 m. This is comparable to other positioning systems previously developed for WLANs.

STARNET is a fiber optic based network which facilitates the interconnection of distributed Local Area Networks. Configured as a sixteen pointed star topology with a multiprocessor based controller at the center of the star (named the Central Switch). STARNET is capable of scheduling calls from users connected to User Access Nodes located at the points of the star. Messages are passed from one node to another through the Central Switch via duplex fiber optic lines connecting each node to the center. / This paper presents a multiprocessor based design of the User Access Node. The hardware and software structure is examined in depth, providing solid guidelines for the physical construction of the unit. The performances of statistical STARNET models using parameters obtained from the design (and three different Central Switch models) are plotted and compared for five different examples of external traffic. The model analysis gives an indication of the expected message delays, supporting the feasibility of the design.

Networks play an important role in today's information age. The need to share information and resources makes networks a necessity in almost any computing environment. In many cases, the network can be thought of as a large, distributed computer, with disks and other resources on big systems being shared by smaller workstations on people's desks.Security has long been an object of concern and study for both data processing systems and communications facilities. With computer networks, these concerns are combined, and for local networks, the problems may be more acute. Consider a fullcapacity local network, with direct terminal access to the network, data files, and applications distributed among a variety of processors. This network may also provide access to and from long-haul communications and be part of an internet. Clearly, the task of providing security in such a complex environment is quite involved.The subject of security is a broad one and encompasses physical and administrative controls. The aim of this research is to explore the security problems pertaining to Ethernet networks. Different approaches to obtain a secure Ethernet environment are also discussed. / Department of Computer Science

Thesis (M.S.)--Eastern Illinois University, 2009. / Includes bibliographical references (leaves 58-60).

Thesis (M. App. Sc.)--Carleton University, 2004. / Includes bibliographical references (p. 122-126). Also available in electronic format on the Internet.

Thesis (M.S.)--University of Copenhagen, 1995. / "Department of Computer Science, University of Copenhagen"--Cover. "Summer 1995." Includes bibliographical references.

Dissertation (MCIS - Computer and Information Sciences) -- AUT University, 2008. / Includes bibliographical references. Also held in print (ix, 65 leaves : ill. ; 30 cm.) in City Campus Theses Collection (T 621.385 WU)

Thesis (M.S. in Computer Science)--Naval Postgraduate School, September 2009. / Thesis Advisor(s): Gibson, John ; Singh, Gurminder. "September 2009." Description based on title screen as viewed on 5 November 2009. Author(s) subject terms: IEEE 802.15.4, wireless sensor network, remote imaging, wireless. Includes bibliographical references (p. 79-81). Also available in print.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 2004. / Thesis advisor(s): Gamani Karunasiri, Xiaoping Yun. Includes bibliographical references (p. 47-50). Also available online.

Thesis (M.S. in Computer Science)--Naval Postgraduate School, March 2004. / Thesis advisor(s): Curtis Blais. Includes bibliographical references (p. 49-50). Also available online.