For integration between application-systems in a global context, interoperability needs to be established on a global level; global interoperability, in turn, is based on a global common application-interface. This is achieved through resolving differences in, inter alia, protocol profiles, among participants in the global network. ebXML is used as the point of departure. A messaging framework, which is based on existing Web technology and standards, is proposed. Certain security and Web service standards are examined to determine specific parameters for an interoperable secure messaging environment. A security based framework comprising a predefined message format and architecture is investigated for a secure interoperable global electronic marketspace.

Research shows how M-Commerce has managed to find its way to previously inaccessible parts of the world as a major Information and Communication Technologies (ICT) tool for development due to widespread introduction of mobile phones in remote areas. M-Commerce has offered valuable advantages: anytime, anywhere, more personal, more location-aware, more context-aware, more age aware, always online and instant connectivity. But this is not without its problems, of which security is high on the list. The security issues span the whole M-Commerce spectrum, from the top to the bottom layer of the OSI network protocol stack, from machines to humans. This research proposes a threat-mitigation modular framework to help address the security issues lurking in M-Commerce systems being used by marginalised rural community members. The research commences with a literature survey carried out to establish security aspects related to M-Commerce and to determine requirements for a security framework. The framework classifies M-Commerce security threat-vulnerability-risks into four levels: human behaviour and mobile device interaction security, mobile device security, M-Commerce access channel security, wireless network access security. This is followed by a review of the supporting structures or related frameworks that the proposed framework could leverage to address security issues on M-Commerce systems as ICT4D initiatives. The proposed security framework based on the requirements discovered is then presented. As a proof-of-concept, a case study was undertaken at the Siyakhula Living Lab at Dwesa in the Eastern Cape province of South Africa in order to validate the components of the proposed framework. Following the application of the framework in a case study, it can be argued that the proposed security framework allows for secure transacting by marginalised users using M-Commerce initiatives. The security framework is therefore useful in addressing the identified security requirements of M-Commerce in ICT4D contexts.

The World Health Organization has recommended Telemedicine to improve health care in developing countries. The objective of this study was to produce Critical Success Factors that will investigate and identify factors that influence the acceptance and continued use of Telemedicine in the Eastern Cape Department of Health, and to suggest ways to sustain this technology from initial adoption (the pilot programme) to full adoption. Sub questions investigated which other facilitating factors, such as management support or previous Information Technology exposure must be present in order for the technology to be adopted successfully. The study made use of a questionnaire to investigate the user acceptance and behaviour of health care workers. A return rate of 76% was achieved. The data was analysed making use of Statistical Package for the Social Sciences (SPSS), specifically the Chi Square test. From these results Critical Success Factors where then formulated to address the problems identified. The Critical Success Factors that were identified include: Implement and disseminate best practice within a legislative framework; Find a champion; Change management strategies; Training; Sustainable finance; Technical issues and Project management principles If these CSFs are addressed before and during the implementation of Telemedicine it will increase the acceptance and use of the technology among health care workers. Critical Success Factors for User Acceptance of Telemedicine in South Africa.

This thesis evaluates the potentials of hybrid fibre and free space optical (FSO) communications access networks in providing a possible solution to an all optical access network. In such network architectures, the FSO link can extend the system to areas where an optical fibre link is not feasible, and/or provide limited mobility for indoor coverage. The performance of hybrid fibre and FSO (HFFSO) networks based on digital pulse position modulation (DPPM), for both the indoor and outdoor environments of the optical access network, are compared with the performance of such a network that is based on conventional on-off keying non-return-to-zero (OOK NRZ) modulation using results obtained through computational and analytical modelling. Wavelength division multiplexing (WDM) and/or code division multiple access (CDMA) are incorporated into the network for high speed transmission and/or network scalability. The impacts of optical scintillation, beam spreading and coupling losses, multiple access interference (MAI), linear optical crosstalk and amplified spontaneous emission noise (ASE) on the performance of hybrid fibre and FSO (HFFSO) access networks are analysed, using performance evaluation methods based on simple Gaussian approximation (GA) and more complex techniques based on moment generating function (MGF), including the Chernoff bound (CB), modified Chernoff bound (MCB) and saddlepoint approximation (SPA). Results in the form of bit error rate (BER), power penalty, required optical power and outage probability are presented, and both the CB and MCB, which are upper bounds, are suggested as safer methods of assessing the performance of practical systems. The possibility of using a CDMA-based HFFSO network to provide high speed optical transmission coverage in an indoor environment is investigated. The results show a reduction in transmit power of mobile devices of about 9 – 20 dB (depending on number of active users) when an optical amplifier is used in the system compared to a non-amplified system, and up to 2.8 dB improvement over OOK NRZ receiver sensitivity is provided by a DPPM system using integrate and compare circuitry for maximum likelihood detection, and at coding level of two, for minimum bandwidth utilization. Outdoor HFFSO networks using only WDM, and incorporating CDMA with WDM, are also investigated. In the presence of atmospheric scintillations, an OOK system is required (for optimum performance) to continuously adapt its decision threshold to the fluctuating instantaneous irradiance. This challenge is overcome by using the maximum likelihood detection DPPM system, and necessitated the derivation of an interchannel crosstalk model for WDM DPPM systems. It is found that optical scintillation worsens the effect of interchannel crosstalk in outdoor HFFSO WDM systems, and results in error floors particularly in the upstream transmission, which are raised when CDMA is incorporated into the system, because of MAI. In both outdoor HFFSO networks (with WDM only and with WDM incorporating CDMA), the optical amplifier is found necessary in achieving acceptable BER, and with a feeder fibre of 20 km and distributive FSO link length of 1500 m, high speed broadband services can be provided to users at safe transmit power at all turbulence levels in clear air atmosphere.

M.Ing. (Electrical and Electronic Engineering) / Since the beginning of telecommunications. more than 100 years ago, systems have been developed through a constant interaction between technical inventions. economic applications and the desire for improved communication facilities to such an extend that there is now a highly efficient communication network whichspans over the entire globe. The still growing demand for data communication. on conventional channels such ascoaxial cables and twisted pairs. made it necessary to develop systems which make use of line codes. In developing countries. like South-Africa. it is not economically feasible to change the existing analog systems to digital systems to enable data communications. In this study. we have done research into the possibility of combining ananalog speech signal with a digital data channel. Ideally the data channel should make use of line codes with low power contents at low frequencies. so that an analog speech channel can be inserted. Different coding methods were used to construct simple encoders and decoders which generate sequences with low power content at low frequencies. The experimental setup used in this thesis. showed that these new line codes exhibit low frequency suppression to such an extend that an analog speech channel can be inserted without the one interfering with the another.

The telecommunications industry is undergoing a metamorphic change. New technologies have made possible a vast panorama of new services. Electronic newspapers, videotelephones, and computer-mediated conferences are but a few of the possibilities. In contrast to technology, most of the other factors affecting the industry (and its infrastructure) have not changed. Government regulations, for example, are based on the 1934 Communications Act. These factors (e.g., consumer behavior, corporate philosophies, energy, and competition) are beginning to change. The Congress is considering a rewrite of the 1934 Communications Act. Competition has become a dominant factor (note that the industry by and large has been a government-regulated monopoly). The outcome of these changes will determine which services will be offered and the extent to which they will be demanded. The problem is to determine which changes will actually occur and, then, forecast their effect. The problem is further complicated by the fact that those individuals and institutions involved in making changes do not know which changes to make. For them, a forecasting system is needed to evaluate the outcome of various changes. A review of the literature was conducted to determine the extent to which the problem was solved. Several forecasts have been generated, but none address the problem in its entirety. Some have examined, in great detail, one or two of the pertinent factors, but ignored the others. Other forecasts have been more global. These assume certain changes will be made. Forecasts are then developed. The problem is that users do not have the option of changing the assumptions. Moreover, most of these forecasters have not specified their assumptions. Following the literature search, an overview of the FORTEL System is given. FORTEL is designed to forecast service and terminal equipment demand. The system synthesizes forecasters' assumptions about industry change with quantitative demand models. The system also provides the forecaster with the ability to change assumptions and evaluate the outcome; i.e., test alternative scenarios. There are three major components: model, user assumptions, and the computer program. The model component consists of four demand models. For each market (residential and business), there are service and terminal models. User assumptions reflect the forecaster's outlook on the future of the telecommunications industry. The assumptions are divided into five categories. The general category reflects assumptions about the industry in general, the economy, societal change, and energy. Technology assumptions deal with the future of a variety of new (and existing) technologies. There are several assumptions about services and terminals. These cover a broad range of factors which will directly affect implementation and demand of a particular service or terminal. The final category includes assumptions about the forecasting technique (quantitative techniques) to be used. The computer program is the synthesizing component of the system. It combines the user assumptions with the models to produce the forecast. It also contains the scenario testing facit of the system. Following a detailed description of each component, an output comparison is given. The author has selected three different sets of user assumptions. The forecasts generated from these sets are compared. The three range from a pessimistic outlook (economic recession and energy crisis) to a very prosperous outlook (exponential growth). The thesis concludes with a chapter on follow-on research and a conclusion.

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