With the rapid adoption of multimedia network technologies, a number of companies and standards bodies are introducing technologies that enhance user experience in networked multimedia environments. These technologies focus on device discovery, connection management, control, and monitoring. This study focused on control and monitoring. Multimedia networks make it possible for devices that are part of the same network to reside in different physical locations. These devices contain parameters that are used to control particular features, such as speaker volume, bass, amplifier gain, and video resolution. It is often necessary for changes in one parameter to affect other parameters, such as a synchronised change between volume and bass parameters, or collective control of multiple parameters. Thus, relationships are required between the parameters. In addition, some devices contain parameters, such as voltage, temperature, and audio level, that require constant monitoring to enable corrective action when thresholds are exceeded. Therefore, a mechanism for monitoring networked devices is required. This thesis proposes relationships that are essential for the proper functioning of a multimedia network and that should, therefore, be incorporated in standard form into a protocol, such that all devices can depend on them. Implementation mechanisms for these relationships were created. Parameter grouping and monitoring capabilities within mixing console implementations and existing control protocols were reviewed. A number of requirements for parameter grouping and monitoring were derived from this review. These requirements include a formal classification of relationship types, the ability to create relationships between parameters with different underlying value units, the ability to create relationships between parameters residing on different devices on a network, and the use of an event-driven mechanism for parameter monitoring. These requirements were the criteria used to govern the implementation mechanisms that were created as part of this study. Parameter grouping and monitoring mechanisms were implemented for the XFN protocol. The mechanisms implemented fulfil the requirements derived from the review of capabilities of mixing consoles and existing control protocols. The formal classification of relationship types was implemented within XFN parameters using lists that keep track of the relationships between each XFN parameter and other XFN parameters that reside on the same device or on other devices on the network. A common value unit, known as the global unit, was defined for use as the value format within value update messages between XFN parameters that have relationships. Mapping tables were used to translate the global unit values to application-specific (universal) units, such as decibels (dB). A mechanism for bulk parameter retrieval within the XFN protocol was augmented to produce an event-driven mechanism for parameter monitoring. These implementation mechanisms were applied to an XFN-protocol-compliant graphical control application to demonstrate their usage within an end user context. At the time of this study, the XFN protocol was undergoing standardisation within the Audio Engineering Society. The AES-64 standard has now been approved. Most of the implementation mechanisms resulting from this study have been incorporated into this standard.

Rural Internet connectivity projects aimed at bridging the digital divide have mushroomed across many developing countries. Most of the projects are deployed as community centred projects. In most of the cases the initial deployment of these projects is funded by governments, multilateral institutions and non-governmental organizations. After the initial deployment, financial sustainability remains one of the greatest challenges facing these projects. In the light of this, externally funded ICT4D interventions should just be used for “bootstrapping” purposes. The communities should be “groomed” to take care of and sustain these projects, eliminating as soon as possible a dependency on external funding. This master thesis presents the design and the implementation of a generic architecture for the management of the costs associated with running a computer network connected to the Internet, The proposed system, called the Network Revenue Management System, enables a network to generate revenue, by charging users for the utilization of network resources. The novelty of the system resides in its flexibility and adaptability, which allow the exploration of both conventional and non-conventional billing options, via the use of suitable ‘adapters’. The final goal of the exploration made possible by this system is the establishment of what is regarded as equitable charging in rural, marginalized communities - such as the community in Dwesa, South Africa.

The introduction of Web Services as a platform upon which applications can communicate has contributed a great deal towards the expansion of World Wide Web technologies. The Internet and computing technologies have been some of the factors that have contributed to the socio-economic improvement of urban and industrial areas. This research focuses on the application of Service-Oriented Architecture (SOA) and Web Services technologies in Information and Communication Technologies for Development (ICT4D) contexts. SOA is a style used to design distributed systems, and Web Services are some of the common realizations of the SOA. Web Services allow the exchange of data between two or more machines in a simple and standardized manner over the network. This has resulted in the augmentation of ways in which individuals in a society and in the world communicate. This research aims to develop a SOA-based system with services that are implemented as Web Services. The system is intended to support communication activities of Dwesa community members. The communication methods identified as the most commonly used in the Dwesa community are Short Message Services (SMSs) and voice calls. In this research we have identified further methods (i.e. Multimedia Message Service, Electronic mail and Instant Messaging) to augment communication activities in Dwesa. The developed system, therefore, exposes SMS Web Service, MMS Web Service, Email Web Service and IM Web Service that are consumed in machine-to-machine, machine-to-person and person-to-person types of communication. We have also implemented a one-stop communication shop, through a web portal which provides interfaces to the different communication modules. Elaborate functional and usability testing have also been undertaken to establish the viability and end-user acceptance of the system respectively. This research has provided the initial validation of the effectiveness of the SOA-based system in ICT4D contexts

The development of electronic commerce (e-commerce) is the most visible business use of the World Wide Web. The primary goal of an e-commerce site is to sell goods and services online. This project deals with developing an e-commerce platform for marginalized communities of the Eastern Cape region, South Africa. An online “shopping mall” to support the marketing of art and crafts from disadvantaged communities is presented, with Linux-Apache-MySQL-PHP (LAMP) as the development environment. Free and Open Source Software has been chosen to develop the virtual shopping mall system because the use of Open Source allows easy localization and extensions to the system developed and long term sustainability, as the source code is available. Also, it might start a “virtuous” circle, whereby young members of the communities hosting art and craft makers become involved in maintenance, and then production, of software systems. One important design constraint from the e-commerce platform presented in this thesis is the possibility for the art and craft makers to manage their shops directly, from the initial loading of their wares to the day-to-day maintenance, such as changes of price or items. The user requirement elicitation and initial field testing were conducted in Dwesa, an area on the wild coast, South Africa. The system currently comprising two shops is live at the time of writing this thesis at www.dwesa.com.

No description available.

The purpose of this project was to explore the use of Web services to solve enterprise computing problems. XML-based Web services allow complex information systems to be subdivided. In order to explore this architectural paradigm, two systems were built: an employee records sytem, and a vacation system.

Multihoming allows nodes to be multiply connected to the network. It forms the basis of features which can improve network responsiveness and robustness; e.g. load balancing and fail-over, which can be considered as a choice between network locations. However, IP today assumes that IP addresses specify both network location and node identity. Therefore, these features must be implemented at routers. This dissertation considers an alternative based on the multihoming approach of the Identifier Locator Network Protocol (ILNP). ILNP is one of many proposals for a split between network location and node identity. However, unlike other proposals, ILNP removes the use of IP addresses as they are used today. To date, ILNP has not been implemented within an operating system stack. I produce the first implementation of ILNP in FreeBSD, based on a superset of IPv6 – ILNPv6 – and demonstrate a key feature of ILNP: multihoming as a first class function of the operating system, rather than being implemented as a routing function as it is today. To evaluate the multihoming capability, I demonstrate one important application of multihoming – load distribution – at three levels of network hierarchy including individual hosts, a singleton Site Border Router (SBR), and a novel, dynamically instantiated, distributed SBR (dSBR). For each level, I present empirical results from a hardware testbed; metrics include latency, throughput, loss and reordering. I compare performance with unmodified IPv6 and NPTv6. Finally, I evaluate the feasibility of dSBR-ILNPv6 as an alternative to existing multihoming approaches, based on measurements of the dSBR's responsiveness to changes in site connectivity. We find that multihoming can be implemented by individual hosts and/or SBRs, without requiring additional routing state as is the case today, and without any significant additional load or overhead compared to unicast IPv6.

Indiana University-Purdue University Indianapolis (IUPUI) / The study of this thesis is focused on reducing the link failure detection time in OSPF network. When a link failure occurs, OSPF protocol detects it using RouterDeadInterval time. This timer is fired only after a predefined time interval, thus increasing the time of convergence after the link failure. There are previous studies to reduce the RouterDeadInterval time, but they introduce other effects which are discussed later in the thesis. So, a novel approach is proposed in this thesis to reduce the link failure detection time with the help of emerging network architecture Software Defined Networking (SDN) and OpenFlow Protocol.

The field buses, and particularly the ‘PROFIBUS’, are currently widely used in automation systems, with the intention to automate industrial applications. It is of the utmost importance that one should understand how these systems operate, because failure to understand may result in improper applications, which can ultimately lead to intense network problems and, consequently, lead to potential catastrophic failures in industrial equipment, as well as compromising the health and safety of the people. This research was the performance evaluation of SAMANCOR PROFIBUS network that controls the chrome manufacturing plant. The problem with the network was that it was failing intermittently. These network failures resulted in loss of production, loss of throughput, compromised quality, downtime due to reworks, high costs in energy used to rework, and equipment damage or failure. One of the OBJECTIVES of the research was to carry out a performance evaluation of the PROFIBUS network in terms of the possible electromagnetic interference (EMI) within the plant’s PLC network. This topic emanated from the network service providers that kept insisting that the network was unstable, due to possible electromagnetic interference caused by possible high voltage cables running next to the plant network cables. This assumption was without fact, and hence the research was conducted. The QUANTITATIVE research method was used to conduct the research, where simulation of the plant network, using external parameters, were used to carry out the research. Furthermore, experiments were conducted and the physical measurements were performed on the network, where parameters derived from these measurements were used to compare the two networks. In essence, the network was tested under known configurations. The manner in which the network was simulated was that of stepping up the electrical current from the external device, and recording the response of the network. A stand-alone network rig was built and used to carry out the tests, and the results were compared with those obtained from the plant network. / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)

In recent years, middleware for mobile social network has attracted the attention of academia, causing the design and development of various approaches by researchers. This type of middleware facilitates and makes more efficient the development process of mobile social networking applications. Furthermore, middleware solutions also abstract the communication process with others applications, allowing the acquisition, persistence and reuse of social context information and location of users, besides providing API so that developers can access this information quickly and build new social applications. With a view to supporting this new trend of research, this thesis proposes a middleware for mobile social networking, called My-Direct, which makes use of Wi-Fi Direct technology together with the Bluetooth, aiming to provide flexible communication between the nodes of the mobile social network. Along with My-Direct also was be created a mechanism for user privacy based on information available on mobile device, so that the execution of social activities occurs just between partners with some degree of affinity. / Nos últimos anos, o tema middleware para redes sociais móveis têm atraído a atenção do meio acadêmico, causando o projeto e desenvolvimento de diversas soluções por parte dos pesquisadores. Esse tipo de middleware facilita e torna mais eficiente o pro­cesso de desenvolvimento de aplicações de redes sociais para o ambiente móvel. Além disso, essas soluções de middleware também abstraem o processo de comunicação entre parceiros e permitem a aquisição, persistência e reuso de informações de contexto social e de localização do usuário, além de disponibilizarem API para que os desenvolvedores possam acessar essas informações rapidamente e construir novas aplicações sociais Tendo em vista colaborar para esta nova tendência de pesquisa, esta dissertação propõe uma arquitetura de middleware para redes sociais móveis chamada de My-Direct que faz uso da tecnologia Wi-Fi Direct em conjunto com o Bluetooth, visando proporci­onar comunicação flexível entre os nós da rede social móvel. Junto ao My-Direct, tam­bém foi criado um mecanismo de privacidade para o usuário baseado em informações disponíveis no dispositivo móvel, de forma que a execução de atividades sociais ocorra apenas entre parceiros com algum grau de afinidade.