Bachelor-Arbeit Univ. St. Gallen, 2006.

Zugl.: Saarbrücken, Univ., Diss., 2010

Fingerprinting methods for positioning is an area of great interest, this thesis presents a study on the Adaptive Enhanced Cell Identity (AECID) fingerprinting method for positioning. By creating a map of the radio characteristics in a geographical region, the AECID method is able to locate a UE by gathering information of the radio conditions of its current location. By performing positioning in this manner, there is no need for additional signaling, which is a better usage of the radio resources. This thesis presents a new approach for the creation of fingerprints together with alternative methodology at each step proposed by the AECID method. These alternatives are implemented and evaluated for real and simulated scenarios. Accuracy performance metrics are discussed based on different formats supported for reporting position. The alternatives presented in this thesis will show not only an enhancement on the accuracy levels but most importantly, the impact of each step on the final performance of the method.

The aim of this project is to analyze a data log of wireless packet traffic, and to produce: (1) models for dynamic fluctuations in wireless channel and link quality, and, (2) a design for real-time communications over the given wireless channel. The models and designs are useful in setting up real-time communications in a vehicular test track (www.astazero.com). The data log came from experimental measurements at the test track. From this data, we fitted simple models for packet losses and retransmissions in the wireless communication system. These models took the form of a combination of a statistical model for the packet losses, with a deterministic model for retransmissions of lost packets. Such fitted models can be used to predict the average quality of vehicle position monitoring based on periodically transmitted position information. Such predictions help us decide the feasibility of safe and reliable conduct of testing with two or more moving test objects.

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Sammanfattning Denna rapport beskriver ett examensarbete som gjordes åt TietoEnator. Målet med examensarbetet var att optimera listhantering i en telekomapplikation. För att utföra detta användes programmeringsspråket C. Uppgiften omfattade fyra delar som bestod av att: - Undersöka den nuvarande implementationen - Föreslå förbättring till den nuvarande implementationen - Implementera den utvalda lösningen - Utföra mätningar samt dokumentera resultaten Undersökningen av den nuvarande implementationen gjordes genom flera olika mätningar för att kunna se exekveringstiderna på operationerna. Förslag till förbättringar till den nuvarande implementationen gjordes genom analysering av olika datastrukturer. Implementationen av den utvalda lösningen blev ett AVL-träd och en hjälplista som är en länkad lista. Mätningar och dokumentation gjordes genom att mäta tider på den gamla och nya implementationen där man sedan jämförde exekveringstiderna. Resultatet blev en klar förbättring som t.ex. sökning av ett objekt vilket blev i snitt 3000 ggr snabbare. Det vi har gjort i detta examensarbete kommer TietoEnator att implementera och utveckla vidare.

The complexity of today's telecommunications systems grows with each new feature introduced. As the number of services an operator provides can be used to gain advantage over competitors the number of services will continue to increase. As the complexity grows, so does the possibility for feature interactions, situations where the operation of features interfere with the operation of other features. Interactions cost more to resolve the later during the introduction of a new feature they are detected. This makes the need for analysis of feature interactions during development preeminent. There exists a multitude of frameworks and techniques for specification and analysis of models of telecommunications systems. However, we have identified that they often impose unnecessary design decisions on the models, making them untoward. In this thesis we propose a framework for specification of models of telecommunications systems. The framework is designed to describe them as general systems of communicating processes in a flexible way which allows alterations to be made late during the design. We also present definitions of interactions and how the interaction definitions are used in the framework to detect undesired interactions. A model for telephony systems is derived through observations made of common telephony concepts and constructs. Delving into concepts early in the design of the system is shown to avoid several sources of interactions. To demonstrate the potential of the framework we present a case study where the system and services described in the first interaction detection contest has been implemented and searched for interactions.

Telecommunication systems are today among the largest and most heterogeneous computer systems that exist. The functionality offered by them is rapidly increasing, by numerous features: call waiting, credit-card billing and call-forwarding to name a few. The realisation of extra services poses a challenge to implementors, in particular since different services are developed at different times and places, by different people. Not only is the number and complexity of services increasing but some vendors want to enable users to tailor their own services and ultimately design them entirely. This of course calls for rigorous control of the services so that they do not come into conflict with the interest of the vendors, other users or surprise the users with their behaviours. One way of aiding the service designers is to provide a service creation environment containing a set of well defined building blocks that would be uniform for all features, irrespective of vendor or service. Such an environment also needs tool support for writing, checking, validating and analysing for possible conflicts. We have constructed a formalism for compactly specifying the interface behaviour of the switching and service logic system underlying a service creation environment, and for specifying the behaviour of components of an environment for service creation. For this formalism we supply tool support in the form of a simulator. We have further made a formalisation, in our framework, of the ITU-T Intelligent Network model, Capability Set-1. The formalisation concerns both the underlying service architecture, in which service logic is perform by a dedicated Service Control Function, and the component language, in which Service Independent Building Blocks are composed to yield new services.

Electromagnetic wave propagation is a well-known phenomenon in the scientific world and when the first telescope was built method of sensing objects excelled afterwords. Research in optical system and infrared is growing day by day but radar system still dominates the world in object sensing. One of the benefits of using electromagnetic waves in a Radar system is that they can create images of areas which cannot be observed with optical light. Radars work on the basic phenomena of an extremely short burst of radio energy which transmit energy that reflects from the object as an echo. This principle is also known as ECHO Principal [13]. This thesis presents a Coffee Can radar system which gives detection of a stationary and moving object. Objects detection is performed on the oscilloscope using a triangular wave transmitted from an antenna, that gets reflected from an object and received on the second antenna. The prototype consists of two antennas one of which is used for transmitting signal and other is used for receiving signal. Voltage control oscillator is used to generate the RF frequency signal and power amplifiers are used before transmitting and receiving the RF signal. The signals are down-converted using a mixer the output of which is observed on an oscilloscope. Detection of the reflected signal can be performed using Doppler shift which can be determined from the velocity of electromagnetic radiation and angular displacement of the reflected waves. The wavelength of the Doppler shift is then used to indicate the detection and ranging of the object. Coffee Can radar operates at 2.4GHz with the output power of 10mW. Triangular wave signal is generated with the help of a wave generator. The radar prototype built in this thesis is used for detection and ranging of two different types of materials. First, is a metal sheet and secondly an aluminum foil.  The detection process is completed by noting the Vpp values reflected from these sheets. Vpp values are measured on the oscilloscope when the signal reflected from aluminum sheet. With the help of a commercial software, aluminum foil presence is detected under the snow. For the future work if the video amplifier is built then the aluminum foil presence can be detected on MATLAB without the help of any commercial software. In future Coffee Can Radar can also be used for surveillance purposes like smart homes, autonomous vehicles and as a jammer. This Radar system can also be used as a data logging system.

Networked systems, such as telecom networks and cloud infrastructures, generate and hold vast amounts of conguration and operational data. The goal of this work is to make all this data available through a real-time search process named network search , which will enable new real-time management solutions. The thesis contains several contributions towards engineering a network search system. Key elements of our design are a weakly structured information model that includes spatial properties, a query language that supports location- and schema-oblivious search queries, a peer-to-peer architecture, a set of echo protocols for scalable query processing, and an indexing protocol for ecient routing for spatial queries. The data against which network search is performed is maintained in local real-time databases close to the data sources. The design follows a bottom-up approach in the sense that the topology for query routing is constructed from the underlying network topology. We have built a prototype of the system on a cloud testbed and developed applications that use network search functionality. Testbed measurements suggest that it is feasible to engineer a network search system that processes queries at low latency and low overhead and that can scale to 100'000 nodes. Simulation results for spatial queries show that query processing achieves response times and incurs overhead close to an optimal protocol, and that query result remains accurate under signicant churn. / <p>QC 20160411</p>