Graduation date: 1994

TASKMASTER is an experimental microcontroller node of a real-time control oriented network which was proposed by James H. Herzog and Tinggui Zhang to demonstrate the feasibility of a task oriented control structure in performing distributed control actions. This study is a continuation of research involving the TASKMASTER network. A high performance microcontroller the 32-bit Motorola MC68332 has been used in this study to implement a node of the TASKMASTER network. Use of the MC68332 with its powerful peripheral subsystems offers significant scope for improvement of the overall performance of the network in addition to strengthening its control processing capabilities. An 8-bit microcontroller the Intel 8052 has also been used to implement a node of the network. A high-level language C has been used for coding of the operating system of the network which previously has been coded in assembly. In addition to being more readable, use of a high-level language offers other significant advantages such as portability, smaller code development time and code debugging time and the ability to compare different microcontrollers on a common basis. A performance analysis and comparison between the two microcontrollers used and the language used in coding them was also performed using performance measures designed as part of this study. / Graduation date: 1994

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 255-261).

Thesis (M. Phil.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

The goal of this thesis is to provide an adaptable protocol stack architecture for data fusion applications. Towards the goal, this thesis presents the design of SensorStack, that addresses three key issues. First, towards network-level adaptability, how to dynamically adapt the placement of a fusion application task graph on the network? We have designed a distributed role assignment algorithm and implemented in the context of DFuse, a framework for distributed data fusion. Second, towards node-level adaptability, how to facilitate cross-layering on a node to foster agile adaptation of a node's behavior commensurate with the network-level changes? SensorStack provides information exchange service (IES) as a framework for cross-module information exchange. Finally, towards tying the network and node level adaptability together, control data published in IES needs to be shared across the network. SensorStack uses a probabilistic broadcast based dissemination service (IDS) for control data. We implement SensorStack in TinyOS and Linux to validate the SensorStack design, and use simulation experiments to investigate its network performance. Experiments demonstrate the utility of adaptability in SensorStack to increase application longevity.

As the role of the Internet has been steadily gaining in importance, overlays are increasingly being used to provide new services and to deploy older ones. Some of the services for which overlays have been proposed include multicast, quality of service (QoS), search, and resilient networks. The use of overlays, in turn, has led to more interest in improving their performance. The performance of an overlay network depends significantly on how the network is structured, i.e., the placement of the nodes in the underlying network topology, the links between the overlay nodes and the access links of these nodes. This thesis focuses on algorithms for improving the performance of

Includes bibliographical references (p. 113-119).

M. Tech. Electrical Engineering. / A virtual Mobile Voice over IP (MVoIP) service can be implemented by a Mobile VoIP Operator (MVoIPO) in conjunction with a Mobile Network Operator (MNO). MVoIPOs do not operate their own mobile network infrastructure. Instead, they use the MNO's packet-based cellular network. However, the coexistence between the MVoIPO and the MNO raises two related problems: first, how to handle interconnection settlements, and second, how to (inter)connect the two operators to make such settlements. This dissertation uses a game-theoretic modelling approach to show that it is mutually beneficial economically if the MNO allows the MVoIPO to operate on its network. Further, a Service Level Agreement (SLA)-based Transparent Settlement Agreement (TSA) model is proposed to solve the first problem. The TSA model algorithm calculates the MVoIPO's throughput distribution at the edge of a UMTS Core Network (CN). This facilitates the determination of levels of conformance to the pre-set throughput thresholds and, subsequently, the issuing of compensation to the MVoIPO by the MNO after generating an economically acceptable volume of traffic. Further, possible network architecture to solve the second problem is suggested, by combining the TSA model algorithm, the UMTS CN, the IP Multimedia Subsystem (IMS), and the Online Charging System (OCS)

published_or_final_version / abstract / toc / Computer Science and Information Systems / Master / Master of Philosophy

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