Application of the conditioned network concept in high frequency power line carrier

The aim of the research described in this thesis was to investigate the possible use of underground Low Voltage Distribution Networks as a medium for the propagation of high frequency communication and data signals. Although the results and observations presented are based upon work carried out on a typical UK urban underground network, the same principles apply to most European underground Low Voltage Distribution Networks. The work was based around the use of frequencies greater than 1 MHz; these high frequencies provide enough bandwidth for a number of value added services to be offered in addition to the more usual Utility requirements for remote meter reading and load control. The research resulted in the development of an in-line filter element designed to limit the amount of Power Line Carrier noise egress from a distribution network whilst at the same time reducing the amount of high frequency noise entering the network. The effects of the Electricity Distribution Network on high frequency signals are discussed in some detail. All Power Line Carrier systems must be capable of operating in the presence of noise. Network topology and individual network elements have a significant effect on high frequency signals; a number of topologies are described and the effects of changes in characteristic impedance and discontinuities are discussed. The results and observations were largely obtained from a Low Voltage Electricity Distribution Network in Kendal, Cumbria. The limited availability of expensive high frequency test equipment resulted in the need to develop unique testing procedures; these are described in full. Sample results from the tests undertaken in Kendal are presented and discussed. The Conditioned Network concept is outlined and the design rules used to develop the in-line Conditioning Unit highlighted. A mathematical model for the filter element of the Conditioning Unit is developed and compared to empirical results obtained from laboratory experiments

Analysis and Design of a secure WLAN solution for Cobre Las Cruces

Cobre Las Cruces is a renowned copper mining company located in Sevilla, with unexpected problems in wireless communications that have a direct affectation in production. Therefore, the main goals are to improve the WiFi infrastructure, to secure it and to detect and prevent from attacks and from the installation of rogue (and non-authorized) APs. All of that integrated with the current ICT infrastructure. This project has been divided into four phases, although only two of them have been included into the TFC; they are the analysis of the current situation and the design of a WLAN solution. Once the analysis part was finished, some weaknesses were detected. Subjects such as lack of connectivity and control, ignorance about installed WiFi devices and their localization and state and, by and large, the use of weak security mechanisms were some of the problems found. Additionally, due to the fact that the working area became larger and new WiFi infrastructures were added, the first phase took more time than expected. As a result of the detailed analysis, some goals were defined to solve and it was designed a centralized approach able to cope with them. A solution based on 802.11i and 802.1x protocols, digital certificates, a probe system running as IDS/IPS and ligthweight APs in conjunction with a Wireless LAN Controller are the main features

Fieldbus technology in industrial automation

http://ieeexplore.ieee.org/Fieldbus technology in industrial automation is not only relatively complex because of the number of solutions possible, but also, and above all, because of the variety of applications. Ironically, these in turn are responsible for the multitude of solutions available. If the analysis of the basic needs is relatively standard, as they will always involve connecting sensors, actuators, and field controllers with each other, the options in architecture are numerous and can impose the need for certain services. The required performances themselves and the quality of service expected fundamentally depend on the applications. This article traces this technology from its beginnings, which go back to the first industrial networks in the 1970's. The principal stages of development are recounted, from the initial requirement specifications to the current state of international standardization. The diverse technical solutions are then analyzed and classified. In particular, we study the temporal aspects, the medium access control protocols and application relationships

Telecommunications Networks

This book guides readers through the basics of rapidly emerging networks to more advanced concepts and future expectations of Telecommunications Networks. It identifies and examines the most pressing research issues in Telecommunications and it contains chapters written by leading researchers, academics and industry professionals. Telecommunications Networks - Current Status and Future Trends covers surveys of recent publications that investigate key areas of interest such as: IMS, eTOM, 3G/4G, optimization problems, modeling, simulation, quality of service, etc. This book, that is suitable for both PhD and master students, is organized into six sections: New Generation Networks, Quality of Services, Sensor Networks, Telecommunications, Traffic Engineering and Routing

What happens during a blackout: Consequences of a prolonged and wide-ranging power outage

Power outages in Europe and North America in recent years have given a lasting impression of the vulnerability of modern and high-tech societies. Although the power supply was interrupted for a week at most and only locally, massive functional and supply disruptions, threats to public order and damage amounting to billions of euros have already become apparent. This book shows what consequences a prolonged and widespread power blackout could have on society and its critical infrastructures and how Germany is prepared for such a large-scale disaster. By means of comprehensive consequence analyses, the authors drastically demonstrate that after only a few days, the supply of the population with (vital) goods and services can no longer be guaranteed in the affected area. It is also made clear that considerable efforts are required to increase the sustainability of critical infrastructures and to further optimise the capacities of the national disaster management system. The book is based on TAB Report Nr. 141 "Gefährdung und Verletzbarkeit moderner Gesellschaften - am Beispiel eines großräumigen und langandauernden Ausfalls der Stromversorgung"

The design and application of power line carrier communication and remote meter reading for use in integrated services and broadband - integrated services digital networks

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN009939 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

The invisible scissors: Media freedom and censorship in Switzerland

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.At first glance, the very idea of analysing the freedom of the media and of researching censorship in Switzerland seems absurd. After all, the Federal Constitution explicitly guarantees freedom of the media, and censorship is forbidden. Furthermore, this small, federal, multilingual and multicultural landlocked country in the middle of Europe is universally praised as a model of democracy. Indeed, in a country whose people have a far greater say in government than anywhere else, one could easily assume that the freedom of the media is a foregone conclusion. Yet, in reality, this shining image is more than a little tarnished. The "Prototype for Europe" – as the former Federal President of Germany Richard von Weizsäcker once described Switzerland – experiences the same forms and mechanisms of censorship as any other democratic country. Of course, in Switzerland "undesirable" journalists are not threatened with murder, but critically discerning authors do risk becoming social outcasts. Switzerland prohibits governmental pre-censorship, but the advertising industry has on occasion attempted to shape the content of the media by means of post-publication censorship in the form of boycotts. Switzerland is a constitutional state, yet the paragraphs of its penal and civil codes hang over media workers like the sword of Damocles. Then there are structural problems such as the lack of proper journalistic education. However one looks at it, the freedom of the media in Switzerland is officially, materially and structurally restricted. However, most people remain unconcerned by and indeed unaware of this state of affairs. Thomas Jefferson's reminder that, "to preserve the freedom of the human mind then and freedom of the press, every spirit should be ready to devote itself to martyrdom; for as long as we may think as we will, and speak as we think, the condition of man will proceed in improvement”*, has long been forgotten in Switzerland. The Swiss appear to be basking in their country’s reputation as a place without media problems. It therefore came as no surprise to us when, both in our quantitative and qualitative research, many of those interviewed were surprised and even irritated at our 2 questions about possible threats to freedom of the media in Switzerland. Some people even felt that they were being personally attacked and responded along the lines that "Instead of fouling our own nest we ought to describe the advantages of our country and our democratic system". Or: "In comparison with Russia or China we are living in a paradise": It seems that only the most critical among the media personnel, media experts and media scientists are willing to pinpoint the problems faced by the contemporary Swiss media. All the others are convinced that we have the best media on earth. This attitude of part indifference, part ignorance and part wishful thinking, was the catalyst for our research on the freedom of the Swiss media and the potential dangers and mechanisms which threaten it. Our findings reveal that all that glitters is not gold and that the Swiss media scene is, in some ways, reminiscent of a Potemkin village. *Jefferson, Thomas, Letter to William Green Mumford, 18 June 1799 (http://www.positiveatheism.org/hist/quotes/jefferson.htm, consulted 15 June 2006

Implementation of IEC 61850 in Solar Applications

IEC 61850 has become one of the core technologies in the substation automation due its high-speed reliable operation Ethernet-based communication with a high security. Its reliability and performance makes a significant contribution to a fail-safe substation operation. IEC 61850 also allows both vertical and horizontal communications in the substation automation. Main characteristic of IEC 61850 is the use of GOOSE messages. All communication services run parallel via one LAN connection and the same GOOSE message can be broadcasted to several IEDs in once. This results in less wiring and faster data exchange between applications. Moreover, one of the core features of IEC 61850 is the interoperability between IEDs from different vendors. The separation of communication and data model allows to reliably retaining engineering data for a long time even if when upgrading or changing the system. IEC publishes updated documentations every while and add new parts to the standard due to the rabidly increase of IEC 61850 applications demand. As the market of solar applications has been increasing last few years, hence, the needs of new technologies to be implemented in solar applications is increasing as well. This thesis beside several other current researches nowadays is investigating the implementation of IEC 61850 in solar applications. The thesis outlines the current needs of solar applications by collecting statistical data using two surveys then concludes the implementation requirement. In the end of the research, IEC 61850 Data sets and current used parameters by Vacon were compared, and simulation example of photovoltaic array is given to conclude the benefits of using IEC 61850 in solar systems.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

The radio spectrum requirements of broadband power line telecommunications systems.

There is concern among short wave (HF) radio users that broadband Power Line telecommunications (PLT) systems could cause serious interference to their services. The purpose of my research was to identify the factors that determine the performance of broadband PLT systems and to investigate how to maximise system performance while minimising the effect of PLT on HF radio systems. The study concentrates on the requirements for Access Band systems used to provide local loop service operating on 230/400V three-phase Low Voltage mains distribution networks. The basis of the study is a comprehensive set of measurements made on Low Voltage mains distribution networks in the UK, mainland Europe and Australia. The new approach to PLT band planning taken in this thesis uses Claude Shannon's information theory to predict the data capacity of arbitrary 3MHz sub bands. The results of the measurement programme are used to determine an optimum frequency band plan for PLT systems, taking account of the needs of the systems and the protection of other users of the HF spectrum. An example of how the proposed band plan can be used on a typical LV distribution network is included. The use of the mathematical models with the results of the attenuation, noise and emission measurements show that it is possible to improve on both the frequency band plans proposed in current PLT standards and the nonstandard frequency usage of many PLT trial systems. This will facilitate the achievement of competitive performance without causing undue radio interference, thus potentially making broadband PLT more acceptable to the HF radio community. The choice of modulation and coding systems required to deliver the predicted performance in the presence of transient interference is also discussed