• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 11
  • 5
  • 2
  • 1
  • Tagged with
  • 21
  • 21
  • 9
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Accurate prediction of scintillation degradation applicable to satellite communications systems design

Savvaris, Ali January 2004 (has links)
Satellite communication was operated exclusively in C-bandprior to 1970. Since then there has been an explosive growth in the demand for telecommunication services that are either only feasible via satellite or very cost effective by that means. This has prompted a steady growth in the utilization of higher frequencies in the Ku-band and above. The higher frequencies offer various advantages such as increased bandwidth, smaller antennas, and smaller satellite footprints that give higher EIRP permitting greater frequency reuse. The main drawback however is that they are subject to more severe propagation degradation. The small size antennas employed in VSAT and USAT systems significantly reduce the cost of earth station terminals and also eliminate tracking requirements, but they lose the mitigating effect of aperture averaging and hence experience stronger scintillation. The result is random fading and enhancement in the received signal amplitude, which will have a significant impact on the performance of low-margin communication systems operating at high frequencies (> ~10GHz) and low elevation angles, and utilising small antennas. Scintillation effects need to be considered in the design and link-budget calculations of these systems. In this thesis, the results are shown of an extensive measurement analysis of tropospheric scintillation, using the ITALSATsatellite beacon signals at 18.7, 39.6 and 49.5 GHz, recorded at Sparsholt, U.K., at an elevation angle of 29.9°. The analysis was carried out in order to study the effects of scintillation due to tropospheric turbulence and their impact on satellite digital communication systems. The first part of the thesis deals with the preprocessing of raw propagation data and presents various statistical results relating to the stationary aspects of the scintillations, i. e. pdf of amplitude and intensity; long and short term statistics of amplitude scintillation distributions. The relationship of scintillation with link parameters and meteorological parameters are also studied. The second part of the thesis investigates the dynamic characteristics of scintillation. It examines the observed effects of wind and cloud presence on the intensity and power spectrum of tropospheric scintillation and then moves on to present results relating to the analysis of the instantaneous frequency scaling of scintillation. In the third part of the thesis scintillation fade and enhancement duration statistics are presented for various threshold signal levels, and their use in fade countermeasures is examined. Finally, a study of adaptive fade countermeasures (FCM) that could be used for systems operating at Ka-band and above for mitigating the effects of scintillations and rain attenuation is presented. The last part, presents an improved global prediction model for both the long-term standard deviation and the signal level distribution of tropospheric scintillation. The model is validated using measurement results from satellite links in Europe, the United Sates and Japan at frequencies from 11 GHz to 50 GHz, and path elevation angles 5.8° to 40°.
2

Characterizing the HTTPS Trust Landscape : - A Passive View from the Edge / Karaktärisering av HTTPS Förtroende-Landskap

Ouvrier, Gustaf January 2019 (has links)
Our society increasingly relies on the Internet for common services like online banking, shopping, and socializing. Many of these services heavily depend on secure end-to-end transactions to transfer personal, financial, or other sensitive information. At the core of ensuring secure transactions are the TLS/SSL protocol and the ``trust'' relationships between all involved partners. In this thesis we passively monitor the HTTPS traffic between a campus network and the Internet, and characterize the certificate usage and trust relationships in this complex landscape. By comparing our observations against known vulnerabilities and problems, we provide an overview of the actual security that typical Internet users (such as the people on campus) experience. Our measurements cover both mobile and stationary users, consider the involved trust relationships, and provide insights into how the HTTPS protocol is used and the weaknesses observed in practice.
3

Mobile phone penetration in northern India : the effects on small scale businesses /

Wedin, John. Lindström, Karin. January 2008 (has links)
Bachelor's thesis. / Format: PDF. Bibl.
4

Product & Pricing Standardization within the Global Mobile Network Operator Industry

Laws, Richard, Mo, Ni January 2015 (has links)
Aim: This study focuses on the degree to which mobile network operators standardize or adapt their product and pricing strategies amongst their foreign subsidiaries. Method: 10 mobile network operators with large overseas business investments and 70 of their foreign majority-owned subsidiaries are included in this empirical analysis. Variables related to data, SMS, Voice, and other relevant variables, are selected to represent ‘product’ marketing characteristics; and number of plans and specific price points across three ‘price baskets’ to represent ‘price’ marketing. Results & Conclusion: MNOs exhibited a moderate degree of standardization in terms of product design, with a lesser degree of standardization for price. Standardization scores were highly positively correlated to subsidiary operations in markets within the same region and level of economic development as the domestic market. There is also a notable clustering of marketing approaches in the Sub-Saharan African region. Implications: Existing research on standardization is reinforced by these results. Future research on the MNO industry, if global in nature, will need to account for the large degree of differences between markets. If focused on specific regions, studies can proceed on the basis of similarity in marketing strategies. Contribution: This is the most recent quantitative study on standardization in the MNO industry carried out in the last 10 years. Since that time the industry has also undergone significant changes.
5

Telecommunication and the allocation of scarce resources and / or essential facilities in terms of the Competition Act 98 of 1998 of South Africa

Dinkelmann, Cheryl Terese January 2014 (has links)
This dissertation aims to evaluate the allocation of essential facilities and / or scarce resources in the telecommunication industry in terms of the abuse of dominance provisions under the Competition Act 98 of 1998. Chapter 1 sets the scene by setting out the history of competition law in South Africa, and the policy considerations that lead to the promulgation of the Competition Act 98 of 1998 in its current form. This is followed by a brief examination of the scope, purpose and application of the Act, including the conduct regulated by the Act. Chapter 1 explores the functions of the Competition Authority in South Africa, and the various enforcement bodies created under the Act. In order to provide context, and to introduce the telecommunication industry, the dissertation briefly discusses concurrent jurisdiction between the Competition Authority and the Telecommunication Regulatory Authority (ICASA). Chapter 1 concludes with a description of radio frequency spectrum; and sets out the scope of the dissertation. Chapter 2 sets out the market definition for radio frequency spectrum, which is defined broadly as the national product market for radio frequency spectrum. The dissertation is limited to the telecommunication industry, thus the market definition is defined only within the context of this industry. After setting out the market definition and identifying the key players in the market for radio frequency spectrum in the telecommunication industry, the dissertation proceeds to discuss the abuse of dominance provisions under the Competition Act, the essential facilities doctrine and scarce resources under the Act. This discussion includes a description of how the doctrine of essential facilities was introduced into our law, a discussion of the relevant case law and a comparative approach of the status in the European Union and the USA. The concept of abuse of dominance and its application in South Africa, the European Union and the USA is described. In conclusion, Chapter 3 compares essential facilities and scarce resources. It is submitted that radio frequency spectrum is a scarce resource and should be dealt with under the abuse of dominance provisions of the Competition Act. Chapter 4 analyses the allocation of radio frequency spectrum in South Africa. It describes the Regulatory Authority and the empowering provisions under the Electronic Communications Act, under which ICASA is empowered to allocate radio frequency spectrum, including the recent policy directions of the Department of Communication. A discussion of the various competition issues that could influence the allocation of radio frequency spectrum follows, specifically with regard to the recent policy directions of the Department of Communications. A brief summary of the views of some of the main industry players in South Africa on the policy directions sets out the concerns of the industry in general, and their reaction to the policy directions. In the concluding Chapter, it is submitted that the abuse of dominance provisions of the Competition Act should be applicable to the allocation of radio frequency spectrum. The reason for this statement is that ICASA often obtains a de facto dominant position with regard to the allocation of an essential facility and / or a scarce resource, such as radio frequency spectrum. Thus it is submitted that the regulator is in a position of dominance which allows it to use regulation as a tool to act anti-competitively. The final Chapter concludes that a wider interpretation of the abuse of dominance provisions is necessary to ensure fair and efficient allocation of radio frequency spectrum. A brief discussion of the policy directions suggests that although, on the face of it, the directions are in line with the provisions of the Competition Act, the method of allocation has scope for anti-competitive allocation by a de facto dominant regulatory authority. It is submitted that more attention must be paid to the actual methods of allocation of radio frequency spectrum, and that a fine balance is required to ensure that spectrum allocation is transparent and efficient. In closing, the dissertation mentions the Electronic Communications Amendment Bill (Government Gazette No. 35525 18 July 2012), which aims to introduce a Spectrum Management Agency to oversee the allocation of radio frequency spectrum in the future. / Dissertation LLM --University of Pretoria, 2014 / am2014 / Mercantile Law / Unrestricted
6

Telecommunication Services’ Migration to the Cloud : Network Performance analysis

Albarrán Munoz, Isaac, Parras Ruiz De Azúa, Manuel January 2012 (has links)
Nowadays, telecommunication services are commonly deployed in private networks, which are controlled and maintained by the telecommunication operators themselves, by co-location services providers, or, to some extent, by their hardware and software providers. However, with the present development of cloud computing resources, one might consider if these services could and should be implemented in the Cloud, thus taking advantage of cloud computing’s high availability, geographic distribution, and ease of usage. Additionally, this migration could reduce the telecommunication operators’ concerns in terms of hardware and network maintenance, leaving those to the Cloud computing providers who will need to supply a highly available and consistent service, to fulfill the telecommunication services’ requirements. Furthermore, virtualization provides the possibility of easily and rapidly changing the Cloud network topology facilitating the addition and removal of machines and services, allowing telecommunication services providers to adapt to their demands on the fly. The aim of this thesis project is to analyze and evaluate the level of performance, from the network point of view, that can be achieved when using Cloud computing resources to implement a telecommunication service, carrying out practical experiments both in laboratory and real environments. These measurements and analyses were conducted using an Ericsson prototype mobile switching center server (MSC-S) application, although the results obtained could be adapted to other applications with similar requirements. In order to potentially test this approach in a real environment, a prior providers’ survey was utilized to evaluate their services based on our requirements in terms of hardware and network characteristics, and thus select a suitable candidate environment for our purposes. One cloud provider was selected and its service was further evaluated based on the MSC-S application requirements. We report the results of our bench-marking process in this environment and compare them to the results of testing in a laboratory environment. The results of both sets of testing were well correlated and indicate potential for hosting telecommunication services in a Cloud environment, providing the Cloud meets the requirements imposed by the telecom services. / Actualmente, los servicios de telecomunicaciones se implementan comúnmente en redes privadas, controladas y mantenidas por los operadores de telecomunicaciones, por proveedores de servicios de colocación o, hasta cierto punto, por proveedores de hardware y software. Sin embargo, con el presente desarrollo de la tecnología de ’Cloud computing’, se puede considerar la posibilidad de implementar servicios de telecomunicaciones en la nube, aprovechando su alta disponibilidad, distribución geográfica y facilidad de uso. Además, este cambio puede reducir las preocupaciones de los operadores en relación al mantenimiento del hardware y de la red, delegando en los proveedores del servicio de ’Cloud computing’, los cuáles deberán proporcionar un servicio consistente, cumpliendo así con los requisitos de los servicios de telecomunicaciones. Por otra parte, la virtualización propociona la posibilidad de cambiar rápida y fácilmente la topología de la red, facilitando la adición y supresión de maquinas y servicios, y, por tanto, permitiendo a los operadores adaptarse a sus necesidades sobre la marcha. El objetivo de esta tésis es analizar y evaluar en nivel de rendimiento, desde el punto de vista de la red, que se puede conseguir usando recursos de ’Cloud computing’ para implementar un servicio de telecomunicaciones, llevando a cabo experimentos tanto en el laboratorio como en un entorno real. Estos análisis fueron realizados utilizando un prototipo de un servidor de conmutación móvil (MSC-S) de Ericsson, aunque los resultados pueden adaptarse a otras aplicaciones con unos requisitos similares. Para probar esta propuesta en un entorno real, se realizó una encuesta de proveedores de servicios de ’Cloud computing’, con el objetivo de evaluar sus servicios teniendo en cuenta nuestros requisitos de hardware y red. Finalmente, un proveedor fue escogido y su servicio evaluado basándonos en los requisitos de la aplicación MSC-S. En este documento proporcionamos los resultados de esa evaluación y los comparamos con los obtenidos en el laboratorio. Los resultados de ambas evaluaciones fueron satisfactorios e indican la posibilidad de implementar servicios de telecomunicaciones en la nube, siempre que la nube cumpla los requisitos impuestos por dichos servicios de telecomunicaciones. / Nuförtiden är telekommunikationstjänster ofta uppsatta i privata nätverk, som kontrolleras och underhålls av teleoperatörerna själva, av samlokaliserande tjänsteleverantörer eller i viss utsträckning av deras hårdvaruoch programvaru-leverantörer. Med den nuvarande utvecklingen av Cloud Computing-resurser kan man dock överväga om dessa tjänster kan och bör genomföras i ett Cloud, vilket drar fördel av Cloud Computings höga tillgänglighet, geografiska spridning, och enkla användning. Denna migration minskar även teleoperatörernas oro angående hårdvaru- och nätverks-underhåll genom att överlåta detta till Cloud Computing-leverantörerna, som kommer att behöva leverera en hög tillgänglighet och konsekvent service för att uppfylla telekommunikationstjänsternas krav. Dessutom ger virtualisering möjlighet att enkelt och snabbt ändra ett Clouds nätverkstopologi, vilket underlättar tillägg och borttagning av maskiner och tjänster, vilket hjälper teleoperatörer att snabbt anpassa sig till deras krav. Målet med examensarbetet är att analysera och uppskatta prestandan, från nätets perspektiv, som kan uppnås vid användning av Cloud Computingresurser för att genomföra en teletjänst, genom praktiska experiment både i laboratorium och i verkligheten. Dessa mätningar och analyser utfördes med en prototyp av en Ericsson mobilomkopplingscentralserverapplikation (MSCS), även om de erhållna resultaten skulle kunna anpassas till andra program med liknande krav. För att potentiellt kunna testa denna metod i en verklig miljö användes en tidigare leverantörs undersökning för att utvärdera deras tjänster baserat på våra krav på hårdvara och nätverksegenskaper, och genom detta välja en lämplig kandidatmiljö för våra syften. En Cloud-leverantör valdes och dess tjänster utvärderades vidare baserat på MSC-Ss applikationskrav. Vi redovisar resultatet av vår testprocess i den här miljön och jämför det med resultaten av tester i laboratoriemiljö. Resultaten från båda uppsättningarna av tester var väl korrelerade och visar på potentialen av att implementera telekommunikationstjänster i en Cloud-miljö, om detta Cloud uppfyller de kraven som ställs av telekommunikationtjänsterna.
7

Построение модели распределения партнёрских услуг на примере телекоммуникационного оператора : магистерская диссертация / Building a model of distribution of partner services on the example of a telecommunications operator

Свалов, С. А., Svalov, S. A. January 2019 (has links)
Российский рынок телекоммуникаций находится в поиске новых направлений развития, включая партнёрства. Целью магистерской диссертации является разработка и апробация экономической модели распределения партнёрских услуг на примере телекоммуникационного оператора. Анализ основывался на изучении научно-периодической литературы, изучении существующих особенностей телекоммуникационных услуги и специфики распределения услуг. В качестве источников информации использовались нормативно-правовые акты, база публикаций Российского индекса научного цитирования, представленная на ресурсе Elibrary, данные корпоративной статистики по тематике исследования, данные управленческой отчетности и внутренние документы исследуемого предприятия. В ходе написания магистерской диссертации была разработана и апробирована модель распределения партнёрских услуг на примере телекоммуникационного оператора. Использование разработанной модели нацелено на повышение эффективности взаимодействия клиентов, телекоммуникационного оператора и его партнёров. / The purpose of the master's thesis is to develop and test the economic model of distribution of partner services on the example of a telecommunications operator. The analysis was based on the study of scientific and periodical literature, the study of the existing features of telecommunication services and the specifics of the distribution of services. As sources of information we were used legal acts, the database of publications of the Russian Science Citation Index, presented on the Elibrary resource, corporate statistics on the subject of research, management reporting data and internal documents of the enterprise under study. During the work there were developed and tested the model of distribution of partner services on the example of the telecommunications operator. The use of the developed model is aimed at improving the efficiency of interaction between customers, telecommunications operator and its partners.
8

Enhancing customer retention in case of service elimination? An empirical investigation in telecommunications

Stiassny, Alfred, Somosi, Agnes, Kolos, Krisztina 03 1900 (has links) (PDF)
Generally, service industries require a rapid innovation of service portfolios to gain and maintain a competitive advantage. In this context, service elimination is a tool of portfolio renewal, where customer retention is a strategic priority for companies. This is especially so because service elimination usually causes higher churn rates than an average churn in telecommunications. Thus, customer retention is seen as a major aspect in enhancing service elimination success. The purpose of this paper is to investigate the factors that increase customer churn in the case of service elimination. We use one of the three Hungarian telecommunication Operator's databases containing usage data three months before and after Service elimination in the course of a major service package reform. Contract-related information and demographics of 10 065 customers are used to differentiate between high and low churn factors, taking care of a possible sample selection problem. The results show that in the course of service elimination there is a significant positive relationship between price decrease, tenure, interaction intensity on the one, and customer retention on the other side. Besides these, demographics (age and residence) also play an important role in explaining churn rates during service elimination. Furthermore, we find that a higher monthly fee after elimination increases the customer´s usage intensity. This research aims to contribute both to service elimination, as well as to customer retention literature, by hierarchical modeling of retention and usage during service elimination with practical implications for decision-makers in rapidly innovating telecommunication markets. / Series: Department of Economics Working Paper Series
9

Customer Intimacy in Mobile Retail / Customer Intimacy in Mobile Retail

Míček, Martin January 2009 (has links)
The master thesis deals with the topic of customer intimacy in mobile telecommunications and describes how the concept of a value-based strategic approach called "customer intimacy" can be applied in telecommunications industry, illustrated on an example of a mobile operator customer relationship lifecycle model. The goal of the thesis is to evaluate mobile telecommunications industry potential for application of the value discipline of customer intimacy and illustrate a high-level framework of Customer Lifecycle Management model as the first transformational step towards customer-intimate organizational design. The thesis sets main hypothesis on the assumption that adoption of the strategy and principles of customer intimacy enable a mobile operator to capture ownership of positive customer experience and secure a sustainable competitive advantage, thereby presenting a powerful counter-measure against the zero-growth industry outlook. As a sub-hypothesis the author postulates the statement that CLM infuses highly-effective methods to capture additional customer value and positively affect mobile operators' profitability. The theoretical part defines characteristics and components of customer value in business relationships and describes truths featuring the new world of competition. This new paradigm of competition leads to the definition of rules for delivering superior value in the following subchapter. Consequently, three value-based strategic approaches towards market leadership (denoted as "value disciplines") are identified and characterized. The second part presents the goals and key principles of the value discipline of customer intimacy and adverts to distinctions in theory and business practice. The author identifies forces driving strategic initiatives focusing on customer value perception and expectations. In this part the opportunities for adoption of customer intimacy in consumer telecommunications industry are also assesses. The penultimate subchapter describes concept of customer experience cycle that will be leveraged in the practical part of the thesis. The last subchapter then examines the importance of service identity for telecoms' successful adoption of the discipline of customer intimacy. The third part is analytical and provides industry research of European telecommunications market. The individual subchapters describe trends in development of fundamental performance indicators. In the fourth, practical part, the author presents the topic of customer lifecycle management. It describes what basic set of expectation customers have towards the relationship with a mobile operator. Then, a conceptual framework of customer lifecycle model is composed and analyzed. The penultimate subchapter pinpoints measures of value based customer profitability, interprets their applicability for decision-making on market investments, and indicates their interlock to value for shareholders. In the last subchapter, a set of recommendations is provided to mobile operators considering infusion of customer intimate principles into their organization. With respect to the practical part and main hypothesis, the author regards the goal of the thesis as fully achieved and the sub-hypothesis of the practical part as confirmed as well. The author used the following methods of research: general research of corporate strategy, marketing and CRM literature, interviews with telecommunications professionals, analysis of corporate financial filings, collection and reading of market research papers and consulting reports, study of statistical data.
10

A Strategic Lean Procurement Model Based on Supplier Approval to Reduce Unplanned Downtime in a Textile Small and Medium-Sized Enterprises

Ramirez-Mitma, Maricarmen, Rojas-Garcia, Jose, Torres-Sifuentes, Carlos, Raymundo, Carlos 01 January 2021 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / In Peru, companies within the textile sector encounter problems such as a decrease in the contribution to an industrial gross domestic product from 10.6 to 7.5%, a decline in financial credits by about 0.7% p.a., and the direct competition of Central American countries across the textile chain. The finishing of fabrics shows the worst performance, with losses of a 38.8% variation in industrial production and a 7.5% growth rate per textile industrial sector. In this scenario, a strategic lean procurement model based on 5S and supplier approval was designed. The lean objective is to streamline workflow in the raw material warehouse that generates excessive lead time to production and leads to unplanned downtime. In addition, supplier approval boosts procurement efficiency and provides strategic value in assessing and planning raw materials to ensure efficient supply. The model is validated through a case study involving a textile small and medium-sized enterprise (SME), and drastic improvements are made. These improvements address the problem of unplanned downtime by reducing its incidence and making economic contributions to the company. / Revisión por pares

Page generated in 0.0978 seconds