Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 92-98). Also available in electronic version.

Dissertation (MCIS) -- AUT University, 2007. / Includes bibliographical references. Also held in print (xii, 71 leaves : ill. ; 30 cm.) in City Campus Theses Collection (T 005.8 ABD)

Thesis (M.S. in Electrical Engineering and M.S. in Systems Engineering)--Naval Postgraduate School, 2004. / Thesis Advisor(s): Tri T. Ha. Includes bibliographical references (p. 95-96). Also available online.

Thesis (Ph. D.)--Cornell University, 1917. / "Reprinted from the Physical review, n. s., vol. x, no. 3, September, 1917.

Thesis (Ph. D.)--University of Pennsylvania. / Cover title. Reprinted from the Physical review, vol. XXV, no. 3, September, 1907.

Thesis (Ph. D.)--Leland Stanford Junior University, 1918. / Reprinted from the Proceedings of the Institute of Radio Engineers, v. 7, no. 5, October, 1919. Errata slip inserted.

Thesis (M.S. in Computer Science) Naval Postgraduate School, Dec. 2001. / "December 2001." Thesis advisor(s): Bert Lundy. Cover title: An assessment of emerging wireless broadband technolofies. Includes bibliographical references (p. 73-75). Also available online.

Thesis (Ph. D.)--Cornell University, 1917. / "Reprinted from the Physical review, n. s., vol. x, no. 3, September, 1917.

WiFi networks have become ubiquitous. However, due to the nature of the radio-wave medium, the performance of 802.11 is unpredictable and highly dependent on the environment. This problem is fundamental to 802.11's decentralized, signal-based airspace arbitration mechanism. When devices have incomplete and inconsistent channel conditions for an overlapping interference domain, their signals alone cannot ensure a fair competition for airspace. As a result, competing flows may suffer from unfair bandwidth distribution if the shared airspace is congested. A useful tool to visualize and diagnose problematic wireless networks is the set of devices interfering with each other at a given time. We say two devices a and b interfere when one of two possible situations occur. First, a is able to sense b's radio signals, though not necessarily decode them, resulting in a unable to send data. Second, a and b aren't in radio range, but their destination devices are, resulting in packet collisions. We call such a set of mutually interfering devices the interference neighbourhood. We present wypy, an online system which merges trace-files and produces a map of interfering devices contained within the trace. wypy is able to identify pairs of devices exhibiting either hidden or exposed terminal interference using a pipeline that consists of trace merging and reconstruction, filtering of simultaneously sending devices, throughput and delay signal calculations, and a test for interference correlation. We evaluate wypy using an in-lab testbed set up in known interference scenarios. / Science, Faculty of / Computer Science, Department of / Graduate

Multicast service is one of the methods used to efficiently manage bandwidth when sending multimedia content. To improve bandwidth utilisation, virtualization is often invoked because of its additional features such as bandwidth sharing and support of services that require high volumes of transactional data. Currently, network providers are concerned with the bandwidth amount for efficient use of the limited wireless network capabilities and the provision of a better quality of service. The virtualization design of a multicast service framework should satisfy several objectives. For example, it should enable the interchange of service delivery between multiple networks with one shareable network infrastructure. Also, it should ensure efficient use of network resources and guarantee users' demands of Quality of Service (QoS). Thus, the design of virtualization of multicast service framework is a complex research study. Due to the bandwidth-related arguments, a strong focus has been put on technical issues that facilitate virtualization in wireless networks. A well-designed virtualized network guarantees users with the required quality service. Similarly, virtualization of multicast service is invoked to improve efficient utilisation of bandwidth in wireless networks. As wireless links prove to be unstable, packet loss is unavoidable when multicast service-oriented virtual artefacts are incorporated in wireless networks. In this thesis, a virtualized multicast framework was modelled by using Generalized Assignment Problem (GAP) methodology. Mixed Integer Linear Programing (MILP) was implemented in MATLAB to solve the GAP model. This was to optimise the allocation of multicast traffic to the appropriate virtual networks. Thus, the developed model allows users to have interchangeable services offered by multiple networks. Furthermore, Network Simulator version 3 (NS-3) was used to evaluate the performance of the virtualized multicast framework. Three applications, namely, voice over IP (VoIP), video streaming, and file download have been used to evaluate the performance of a multicast service virtualization framework in Worldwide Interoperability for Microwave Access (WiMAX) networks using NS-3. The performance evaluation was based on whether MILP is used or not used. The results of experimentation have revealed that there is good performance of virtual networks when multicast traffic is sent over one single virtual network instead of sending it over multiple virtual networks. Similarly, the results show that the bandwidth is efficiently used because the multicast traffic is not delivered through multiple virtual networks. Overall, the concepts, the investigations and the model presented in this thesis can enable mobile network providers to achieve efficient use of bandwidth and provide the necessary means to support services for QoS differentiations and guarantees. Also, the multicast service virtualization framework provides an excellent tool that can enable network providers to interchange services. The developed model can serve as a basis for further extension. Specifically, the extension of the model can boost load balancing in the flow allocation problem and activate a virtual network to deliver traffic. This may rely on the QoS policy between network providers. Therefore, the model should consider the number of users in order to guarantee improved QoS.