Concurrent cell rate simulation of ATM telecommunications network.

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COMPONENT TECHNOLOGIES AND THEIR IMPACT UPON SOFTWARE DEVELOPMENT

Software development is beset with problems relating to development productivity, resulting in projects delivered late and over budget. While the term software engineering was first introduced in the late sixties, its current state reflects no other engineering discipline. Component-orientation has been proposed as a technique to address the problems of development productivity and much industrial literature extols the benefits of a component-oriented approach to software development. This research programme assesses the use of component technologies within industrial software development. From this assessment, consideration is given to how organisations can best adopt such techniques. Initial work focuses upon the nature of component-orientation, drawing from the considerable body of industrial literature in the area. Conventional wisdom regarding componentorientation is identified from the review. Academic literature relevant to the research programme focuses upon knowledge regarding the assessment of software technologies and models for the adoption of emergent technologies. The method pays particular attention to literature concerning practitioner focussed research, in particular case studies. The application of the case study method is demonstrated. The study of two industrial software development projects enables an examination of specific propositions related to the effect of using component technologies. Each case study is presented, and the impact of component-orientation is each case is demonstrated. Theories regarding the impact of component technologies upon software development are drawn from case study results. These theories are validated through a survey of practitioners. This enabled further examination of experience in component-based development and also understanding how developers learn about the techniques. A strategy for the transfer of research findings into organisational knowledge focuses upon the packaging of previous experience in the use of component-orientation in such a way that it was usable by other developers. This strategy returns to adoption theories in light of the research findings and identifies a pattern-based approach as the most suitable for the research aims. A pattern language, placed in the context of the research programme, is developed from this strategy. Research demonstrates that component-orientation undoubtedly does affect the development process, and it is necessary to challenge conventional wisdom regarding their use. While component-orientation provides the mechanisms for increased productivity in software development, these benefits cannot be exploited without a sound knowledge base around the domain

Service creation and deployment on an intelligent network

Active competition in the telecommunications industry has caused a dramatic shift in focus for public network operators. Service designers need to be able to easily and rapidly create services according to the customer’s requirements. This is achievable by using Intelligent Networks (INs). Two primary goals of service development under the Intelligent Network paradigm are rapid service crcation using new software technologies and the minimisation of service development costs through switch vendor independence. This thesis examines the development of an IN architecture and the deployment of two call control services on it using the ITU-T Service Independent Building Block (SIB) methodology. The services are deployed on a narrow-band Excel switching platform. Various aspects of the IN Conceptual Model (INCM) are examined with a particular emphasis on the middle two planes: the Global Functional Plane (GFP) and the Distributed Functional Plane (DFP). Representations of these planes are designed using the ITU-T Specification and Description Language (SDL) [SDL89] and implemented using Telelogic’s SDL Development Tool (SDT). SDL provides capabilities to allow logical structuring of the INCM into its constituent entities, the modelling of communication between these entities and the processing within them. The Intelligent Network paradigm was developed with a view to extendibility. Two call control services, Ringback and Group Call Pickup, are implemented using the SIB methodology. Further services may be created by rearranging the order of execution of the existing SIBs or, if necessary, by adding new SIBs to the architecture. Given the demand for multimedia applications to run on top of emerging broadband networks it is becoming increasingly more important for network operators to study the enhancement and evolution of their IN service platforms in order to cope with new customer requirements. TINA is the leading architecture for multimedia service control and delivery, which defines an emerging open service platform. Migration from IN to TINA is explored in this thesis by considering two individual paths of migration. The first path involves the replacement of the IN service control and management elements (SCF, SMF, SDF) with appropriate TINA Computational Objects while the switching elements (SSF, CCF) remain IN compliant. As there is no one-to-one mapping of IN functional entities to TINA computational objects, an Adaptation Unit is required to facilitate interaction between the legacy IN entities and the TINA Computational Objects. The advantage of this step is that it is possible to keep the investment of deployed IN SSPs while taking advantage of TINA service modelling. The second step involves the introduction of TINA into the switch. In this approach the switch and its switching capabilities may be viewed as a TINA object in itself. Interworking between IN and TINA (as a step towards full migration to TINA) yields a much richer service platform. This service platform facilitates the creation of services that incorporate both IN and TINA features. A TINA service may use pieces of IN functionality and IN services may also use TINA functionality. It is possible to invoke these hybrid services from either a PSTN or a TINA terminal. Three hybrid IN/TINA services were designed to demonstrate the increased resources available to the service designer using such a platform. A user connected to the IN switch invokes the Freephone Service. This service uses a TINA database to convert the 1-800 number to an extension number. The call is then connected using IN switching functionality. The Audio Video Conference, uses TINA computational objects to set up a video stream between participating users while the audio connection is handled by the IN switching functionality. This service is invoked from a TINA terminal. A user connected to the IN switch invokes the Ringback Service but it runs in the TINA domain using both TINA and IN functionality. Therefore, as well as presenting an application of the IN technology, this thesis proposes possible steps towards migration to the TINA architecture

Definition of avionics concepts for a heavy lift cargo vehicle, volume 2

A cost effective, multiuser simulation, test, and demonstration facility to support the development of avionics systems for future space vehicles is defined. The technology needs and requirements of future Heavy Lift Cargo Vehicles (HLCVs) are analyzed and serve as the basis for sizing of the avionics facility although the lab is not limited in use to support of HLCVs. Volume 2 is the technical volume and provides the results of the vehicle avionics trade studies, the avionics lab objectives, the lab's functional requirements and design, physical facility considerations, and a summary cost estimate

The internet integrated intelligent network

This thesis is based on research, design and prototype implementation work done towards defining an Intelligent Network system integrated with Internet functionality and potential services to be provided by such a system. The main driving force behind the project has been an idea to explore the possibility of adding value to services offered by the two most ubiquitous public communication networks of today, by connecting those networks. The goal of the project was to define such a connection and the services that would become possible through its existence. The thesis begins with presenting the background to the project. First of all, it contains the definition and description of Intelligent Networks, as the standard means of providing, in telephone networks, services other than basic connectivity. Further, it defines the Internet and looks at the already existent computer network - telephone network integration systems. In the second part of the thesis, the design of the Internet-Integrated Intelligent Network (DIN) system is laid out. The IHN has been defined using definition methods already standard for the IN, as far as this was possible with regard to the entirely different nature of the Internet. The fundamental role of the World Wide Web Internet application in the functioning of the designed system is shown. Following the research and design work description is an account of the implementation work done to build an IIIN prototype and a group of sample services chosen and implemented to demonstrate IIIN functionality. This account includes a list of demonstration scenarios that have successfully been tested on the system prototype

Soft switching techniques for multilevel inverters

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica