Reliability assessment of telecommunications equipment

This thesis studies the reliability of telecommunications equipment, its components, and the systems made using those components. Special attention is paid to creating stronger links between the reliability analyses performed at different hierarchy levels. The thesis starts with a temperature derating study. It is found out that the generic handbook based procedures may not always be very attractive, as they do not take satisfactorily into account the actual lifetime requirements. An alternative approach is proposed as a remedy to the current situation. Thermal cycling requirement handbooks are surveyed, and based on the findings some enhancements are proposed. Next, a component and product specific approach to create thermal cycling requirements is suggested. When applying the new approach several factors can be taken into account: the product's lifetime requirement, the field environment, the reliability test result, and the statistical distribution of the component population. A new method of how to predict the reliability of a component population that is addressed to several, different field environments is presented. Ceramic, leadless components are studied by testing and by utilizing Engelmaier's analytical solder fatigue model and Finite Element (FE) simulations. A new approach to interpret the solder joint height in conjunction with solder castellations is introduced. Based on this, a very good correlation between the test results and the predictions based on Engelmaier's model can be obtained. The parameter sensitivity of both the Engelmaier's model and the FE analysis are studied and compared. Error margins based on the parameter sensitivity studies are given. Time-averaged hazard rate functions are studied in order to be able to use component level test data in simplistic parts-count method type reliability predictions. Finally, the availability of a full 3rd generation telecommunications network is studied.reviewe

First come, first served: an analysis of pioneer and follower firms' market and nonmarket actions in the European mobile telephone industry

This study examines the relationship between erosion of the first-mover's market share and the differences in competitive behaviour of pioneer firms and followers. Particularly, we pay particular attention to market actions related to innovation, pricing and promotion, and to non-market actions related to judicial issues. The empirical study has been carried out with companies that are present in a dynamic context, such as the European mobile telephone industry. Our results show that when followers take more non-market actions than pioneers the negative effect on the firstentrant's advantage is more significant. On the contrary, we have not found a significant impact of innovating and pricing actions

Blackstarting the North American power grid after a nuclear electromagnetic pulse (EMP) event or major solar storm

The electric power grid is our most critical infrastructure. This key resource provides the energy required for all other infrastructures to function. In modern times, electricity has become necessary to sustain life. The power grid in the U.S. is a target for terrorists and is vulnerable to naturally-occurring events. Numerous assessments have been performed on the vulnerability of our national power grid to both manmade and natural events.1 Two significant wide-area threats against our power grid are solar storms and electromagnetic pulse (EMP) attacks. Solar storms are naturally-occurring events that have the potential to create large-scale blackouts that could potentially affect more than 50% of the U.S. population.2 EMP attacks occur when nuclear weapons are detonated at high altitudes; although there is no threat of direct blast or radiation dangers to humans, EMP events can wreck power grids. Although numerous studies have been conducted on the effects of EMP events and solar storms on the U.S. power grid, little has been done to plan for restarting or “blackstarting” the power grid after such an event. If electricity from unaffected areas is not available, the blackstart process becomes much more challenging. The procedures required to blackstart the power grid following a wide area outage are very different from the procedures used to restart the power grid following the major but limited blackouts that have occurred to date such as the 2003 Northeast blackout. This document develops a starting point for blackstarting the U.S. power grid based on likely effects on critical infrastructures caused by solar storms and EMP events. Previous regional blackstarts were assessed to glean empirical information on aspects that could be extrapolated to a national blackstart contingenc

A Survey on Wireless Security: Technical Challenges, Recent Advances and Future Trends

This paper examines the security vulnerabilities and threats imposed by the inherent open nature of wireless communications and to devise efficient defense mechanisms for improving the wireless network security. We first summarize the security requirements of wireless networks, including their authenticity, confidentiality, integrity and availability issues. Next, a comprehensive overview of security attacks encountered in wireless networks is presented in view of the network protocol architecture, where the potential security threats are discussed at each protocol layer. We also provide a survey of the existing security protocols and algorithms that are adopted in the existing wireless network standards, such as the Bluetooth, Wi-Fi, WiMAX, and the long-term evolution (LTE) systems. Then, we discuss the state-of-the-art in physical-layer security, which is an emerging technique of securing the open communications environment against eavesdropping attacks at the physical layer. We also introduce the family of various jamming attacks and their counter-measures, including the constant jammer, intermittent jammer, reactive jammer, adaptive jammer and intelligent jammer. Additionally, we discuss the integration of physical-layer security into existing authentication and cryptography mechanisms for further securing wireless networks. Finally, some technical challenges which remain unresolved at the time of writing are summarized and the future trends in wireless security are discussed.Comment: 36 pages. Accepted to Appear in Proceedings of the IEEE, 201

Investigation into the impact of wind power generation on demand side management (DSM) practices

The construction of a number of wind farms in South Africa will lay the foundation for the country to embrace the generation of greener energy into the National Grid. Despite the benefits derived from introducing wind power generation into the grid, this source encompasses adverse effects which need to be managed. These adverse effects include the intermittency and lack of predictability of wind. In power systems with a high penetration of wind energy, these effects can severely affect the power system’s security and reliability in the event of significant rapid ramp rates. Recently, many utilities around the world have been exploring the use of Demand Side Management (DSM) and Demand Response (DR) initiatives and programmes to support and manage the intermittency of wind power generation. This report outlines the programmes and benefits of DSM/DR and provides a critical analysis of the challenges facing South Africa with implementing these initiatives. Introducing these programmes necessitates the employment of a number of Smart Grid technologies including Advanced Metering Infrastructure (AMI), next generation telecommunications technologies, smart meters, enterprise system integration and dynamic pricing. These tools and techniques are discussed and their challenges described within the context of South Africa’s current state of the power system. The current practices for DSM/DR in South Africa have been evaluated in this report. Despite, the success of many DSM/DR initiatives in the commercial, industrial and agricultural sectors, it is found that much work is still required in the residential sectors as the current DSM initiatives are not adequate for managing wind power generation. A detailed analysis and recommendations for South Africa’s DR program is then presented based on industry best practices and experiences from other utilities who are currently exploring DSM/DR in the residential sector using Smart Grid technologies

National Conference on ‘Renewable Energy, Smart Grid and Telecommunication-2023

Theme of the Conference: “The challenges and opportunities of integrating renewable energy into the grid” The National Conference on Renewable Energy, Smart Grid, and Telecommunication - 2023 is a platform for industry experts, researchers, and policymakers to come together and explore the latest advancements and challenges in the fields of renewable energy, smart grids, and telecommunication. Conference Highlights: In-depth discussions on renewable energy technologies and innovations. Smart grid integration for a sustainable future. The role of telecommunication in advancing renewable energy solutions. Networking opportunities with industry leaders and experts. Presentation of cutting-edge research papers and case studies. Conference topics: Renewable Energy Technologies and Innovations Smart Grid Development and Implementation Telecommunication for Energy Systems Energy Storage and Grid Balancing Policy, Regulation, and Market Dynamics Environmental and Social Impacts of Renewable Energy Energy Transition and Future Outlook Integration of renewable energy into the grid Microgrids and decentralized energy systems Grid cybersecurity and data analytics IoT and sensor technologies for energy monitoring Data management and analytics in energy sector Battery storage technologies and applicationshttps://www.interscience.in/conf_proc_volumes/1087/thumbnail.jp

Market orientation and firm performance in Ghana's telecommunications industry

This study set out to achieve a comprehensive understanding of the adoption levels of market orientation (MO) in Ghana’s mobile telecommunications industry, and to assess its relationship to performance. This was necessitated by the fact that, in-spite of the superfluity of literature on market orientation and its relationship to performance in developed economies and a few on developing nations such as Ghana, there are hardly any studies on Ghana’s mobile telecommunications industry despite its impressive performance. Furthermore, available studies generally assessed market orientation without incorporating any assessment by customers. The study, in addressing these deficiencies, makes significant contribution to academic knowledge on market orientation. Based on literature reviewed, a conceptual model and nine hypotheses are proposed for this study. Both qualitative and quantitative research methods, underpinned by realism philosophy enabled the assessment of the market orientation performance relationship. Qualitative data collection entailed an in-depth interview of ten senior officers of five mobile telecommunications firms operating in Ghana selected by a judgmental sampling method, whose response was analysed by thematic analysis. Quantitative data was obtained by administering questionnaires on 275 staff selected by a simple random sampling method and 302 subscribers selected by a two-stage process of quota and convenience sampling methods. Confirmatory factor analysis, correlation matrix, structural equation modeling and T-test are utilized in the analysis of the quantitative data and the testing of the hypotheses. The findings of the study established that in Ghana’s mobile telecommunications industry, market orientation is determined by one internal antecedent - top management emphasis with no external antecedent influencing it. The significant effect of market orientation on business performance, customer satisfaction, customer retention, employee commitment and employee esprit de corps have also been established by this study. Finally, the study establishes that, when compared, subscribers and staff assessment of the dimensions of market orientation differed with staff rating them higher than subscribers. Based on the findings, the study recommends the need not only for mobile telecommunication operators to continue in the pursuit of market orientated activities, but also undertake measures to close the market orientation gap between them and their subscribers. Top management should also continue with the pivotal role they are playing in the implementation of market orientation, and enhance their information generation, dissemination and responsiveness processes not only to sustain market orientation but also their performance. Notwithstanding the shortfalls identified, which did not adversely affect outcomes of the study, the study has developed an empirical model for market orientation, firm performance relationship for the mobile telecommunications industry incorporating a comparison of the assessment of the dimensions of market orientation by subscribers and staff. It is hoped that this new model will be used for further studies in both developed and developing countries to test the viability of its application

Telecommunication Economics

This book constitutes a collaborative and selected documentation of the scientific outcome of the European COST Action IS0605 Econ@Tel "A Telecommunications Economics COST Network" which run from October 2007 to October 2011. Involving experts from around 20 European countries, the goal of Econ@Tel was to develop a strategic research and training network among key people and organizations in order to enhance Europe's competence in the field of telecommunications economics. Reflecting the organization of the COST Action IS0605 Econ@Tel in working groups the following four major research areas are addressed: - evolution and regulation of communication ecosystems; - social and policy implications of communication technologies; - economics and governance of future networks; - future networks management architectures and mechanisms

Power Quality Concerns in Implementing Smart Distribution-Grid Applications

This paper maps the expected and possible adverse consequences for power quality of introducing several smart distribution-grid technologies and applications. The material presented in this paper is the result of discussions in an international CIGRE-CIRED joint working group. The following technologies and applications are discussed: 1) microgrids; 2) advanced voltage control; 3) feeder reconfiguration; and 4) demand-side management. Recommendations are given based on the mapping