Having dealt with in-depth analysis of SS#7, GSM and GPRS networks I started to monitor UTRAN interfaces approximately four years ago. Monitoring interfaces means decoding the data captured on the links and analysing how the different data segments and messages are related to each other. In general I wanted to trace all messages belonging to a single call to prove if the network elements and protocol entities involved worked fine or if there had been failures or if any kind of suspicious events had influenced the normal call proceeding or the call’s quality of service. Cases showing normal network behaviour have been documented in Kreher and Ruedebusch (UMTS Signaling. John Wiley & Sons, Ltd, 2005), which provides examples for technical experts investigating call flows and network procedures.
標簽： Performance Measurement Practical Guide UMTS
上傳時間： 2020-06-01
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Wavelength division multiplexing (WDM) refers to a multiplexing and transmission scheme in optical telecommunications fibers where different wavelengths, typically emitted by several lasers, are modulated independently (i.e., they carry independent information from the transmitters to the receivers). These wavelengths are then multiplexed in the transmitter by means of passive WDM filters, and likewise they are separated or demultiplexed in the receiver by means of the same filters or coherent detection that usually involves a tunable local oscillator (laser).
標簽： Multiplexing Wavelength Division
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n the first part of this book, we give an introduction to the basic applications of wireless com- munications, as well as the technical problems inherent in this communication paradigm. After a brief history of wireless, Chapter 1 describes the different types of wireless services, and works out their fundamental differences. The subsequent Section 1.3 looks at the same problem from a different angle: what data rates, ranges, etc., occur in practical systems, and especially, what combination of performance measures are demanded (e.g., what data rates need to be transmitted over short distances; what data rates are required over long distances?) Chapter 2 then describes the technical challenges of communicating without wires, putting special emphasis on fading and co-channel interference. Chapter 3 describes the most elementary problem of designing a wireless system, namely to set up a link budget in either a noise-limited or an interference-limited system. After studying this part of the book, the reader should have an overview of different types of wireless services, and understand the technical challenges involved in each of them. The solutions to those challenges are described in the later parts of this book.
標簽： Communications Wireless Edition 2nd
上傳時間： 2020-06-01
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Mobile radio communications are evolving from pure telephony systems to multimedia platforms offering a variety of services ranging from simple file transfers and audio and video streaming, to interactive applications and positioning tasks. Naturally, these services have different constraints concerning data rate, delay, and reliability (quality-of-service (QoS)). Hence, future mobile radio systems have to provide a large flexibility and scal- ability to match these heterogeneous requirements.
標簽： Communications Wireless Channels MIMO over
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Applications of microelectromechanical systems (MEMS) and microfabrica- tion have spread to different fields of engineering and science in recent years. Perhaps the most exciting development in the application of MEMS technol- ogy has occurred in the biological and biomedical areas. In addition to key fluidic components, such as microvalves, pumps, and all kinds of novel sensors that can be used for biological and biomedical analysis and mea- surements, many other types of so-called micro total analysis systems (TAS) have been developed.
標簽： Applications Technologies Bio-MEMS and
上傳時間： 2020-06-06
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This book is focused on designing and developing Representational State Transfer (REST) platforms in Rails. REST is the architectural style of the Web, consisting of a set of constraints that, applied to components, connectors, and data elements, constitute the wider distributed hypermedia system that we know today: the World Wide Web. There are a few good reasons why it makes more sense to build platforms instead of just products or applications. Platforms are like ecosystems interconnecting different applications, services, users, developers, and partners. Platforms foster innovation through the inputs of their direct collaborators. By providing application programming interfaces (APIs) and software development kits (SDKs), platforms are more customer driven.
標簽： Development Building RESTful Rails
上傳時間： 2020-06-06
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For more than a century, overhead lines have been the most commonly used technology for transmitting electrical energy at all voltage levels, especially on the highest levels. However, in recent years, an increase in both the number and length of HVAC cables in the transmission networks of different countries like Denmark, Japan or United Kingdom has been observed. At the same time, the construction of offshore wind farms, which are typically connected to the shore through HVAC cables, increased exponentially.
標簽： Electromagnetic Transients Cables Power in
上傳時間： 2020-06-07
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A power semiconductor module is basically a power circuit of different materials assembled together using hybrid technology, such as semiconduc- tor chip attachment, wire bonding, encapsulation, etc. The materials involved cover a wide range from insulators, conductors, and semiconduc- tors to organics and inorganics. Since these materials all behave differently under various environmental, electrical, and thermal stresses, proper selec- tion of these materials and the assembly processes are critical. In-depth knowledge of the material properties and the processing techniques is there- fore required to build a high-performance and highly reliable power module.
標簽： Manufacture Electronic Modules Design Power
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This book is based on a Ph.D. research that has been conducted at the Delft University of Technology in the Netherlands in collaboration with Dutch Electricity & Gas Distribution Network Operator, Stedin. This book was written as a result of wider interest that was shown by different industry groups on this topic after its public defence. This inspired the author to modify and publish a practical version of the research for a greater international audience. Therefore, the content of this book is intended for a double audience, on the one hand for those interested in the organisational and management aspects of maintenance.
標簽： Maintenance Electricity Risk-Based Network for
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One of the predominant topics in the domain of the emerging Smart Grid can be seen in standardization. With the combination of existing protection and automa- tion technology with upcoming ICT-based solutions, different interoperability is- sues arise when technologies have to be combined in the infrastructure. Standards have proven to be one of the most striking solutions to actually cope with this topic. Since 2008, this topic has gained much attention in various political and technical agendas.
標簽： Standardization Smart Grids in
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