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  • 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.
11

Granskning av möjliggörande teknik och utveckling av prototyp för geografiskt riktade utskick av SMS

Nordin, Johan, Olsson, Anders January 2004 (has links)
Detta examensarbete på magisternivå genomfördes vårterminen 2004 med Siljan Turism som uppdragsgivare. Målet var att förbättra en befintlig SMS-tjänsten för utskick av erbjudanden genom att möjliggöra geografiskt riktade utskick.Anledningen till att man vill göra denna form av riktade utskick är att man vill kunna minska annonskostnaderna, men fortfarande snabbt nå intresserade konsumenter. Om man idag skulle vilja annonsera ut till exempel biljetter till ett evenemang som äger rum inom den närmaste tiden, där det finns lediga platser kan man endast skicka erbjudanden till samtliga intresserade. Utskicken sker oberoende av var mottagarna befinner sig, trots att de egentligen inte skulle kunna komma fram i tid. Med hjälp av geografiskt riktade utskick skulle man kunna effektivisera utskicken så att de enbart skickas till de som faktiskt har möjlighet att utnyttja erbjudandet.Det befintliga systemet var baserat på en standardiserad tjänst som vi inte hade möjligheter att förbättra. På grund av detta beslutade vi oss för att utveckla en prototyp för att kunna bygga in all ny funktionalitet. Med denna prototyp försökte vi även att eliminera delar av den manuella hantering som krävs med det befintliga systemet.För att kunna realisera dessa riktade utskick behövde vi en typ av positionering som inte existerar idag. De lösningar som finns idag passar inte vår tänkta tjänst. Därför har vi gjort egna undersökningar i GSM och UMTS för att finna lösningsalternativ. Därför kan rapporten vara intressant även för andra än vår uppdragsgivare när det gäller denna typ av geografiskt riktade utskick.
12

The Bus Transportation Management System used New Bus Management Tools

Shen, Hsien-Cheng 09 August 2006 (has links)
Abstracts The Highway Bus Transportation Business to run by the local people was start in 1995. Every company attach importance to service and chair convenience. and have great advance in service and chair convenience . Transportation process was less advance include safety and process convenience. The bus transportation management importance to safety and convenience. Because of new management tools develop .We can use new tools to control transportation process in digital communication. Such as GPS¡]Global Positioning System¡^and GSM (Global System for Mobile Communications) This article is research used new management tools to develop the management system to control the bus driver behavior¡Bthe aberrance reason control¡BThe maintenance of bus¡Bdrive technological processes¡B the bus drive approach¡Bfuel control and immediateness control with GSM. This article instance a company and test the effectiveness management system. Keyword: GPS¡BGSM¡BManagement system
13

Applications of resource optimization in wireless networks /

Björklund, Patrik, January 2006 (has links)
Diss. Linköping : Univ., 2006.
14

Šifrování v mobilní komunikaci

Kmínek, Jakub January 2009 (has links)
No description available.
15

Automated Testbench Generation for Communication Systems

Qu, Xin 09 January 2001 (has links)
This thesis develops semi-automated methods to generate testbenches for VHDL models of communication systems. To illustrate the methods, a VHDL model was constructed for the speech-coding channel of the Global System for Mobile Communication (GSM). GSM is the Pan-European digital mobile telephony standard specified by the European Telecommunication Standards Institute (ETSI). This thesis emphasizes the error detection and error correction procedures that form an important part of the standard. First, a test bench template was generated using "Testbench Pro", a waveform generation tool developed by SynaptiCAD. The template includes a random sequence of speech data. A C program was then developed as a user interface to control the simulation procedure. Using the C program, the user can select a test bench template and specify the input test vectors. The C program adds the user's test vectors to the test bench template to create a final VHDL test bench that is ready for simulation. The testing data is then encoded by the GSM encoder models, passed through the noisy channel model that introduces errors into the data stream and, finally, passed through the GSM decoder models which attempt to correct the channel errors. Sophisticated error detection and error correction algorithms are used in the encoder/decoder models to increase the reliability of data transmission over the noisy channel. Finally, the original speech data is compared to the decoder output to detect any remaining bit errors and to evaluate the system performance. The simulation system is semi-automated. The user selects a set of parameters using the C program interface. A testbench is then automatically created and simulated. Two final report files are automatically generated. No user interaction is needed after the initial parameter selection. Several experiments were performed to illustrate the various features of the automated testbench generation system. / Master of Science
16

Informační infrastruktura telekomunikační společnosti

Feglar, Tomáš January 2007 (has links)
Význam telekomunikačních společností je nesporný. Pozoruhodné je množství finančních prostředků, které přes tyto společnosti proudí. Částky obratu, které dosahují miliardových hodnot, řadí tento sektor mezi finančně nejproduktivnější. Oblast mobilní telekomunikace se dostává za rámec chápání jedince. Množství systémů, kterými každá společnost disponuje je několik set. Orientovat se v problematice je velmi obtížné a udržovat si povědomí o všech novinkách téměř nemožné. Základní stavební kameny velkých mobilních operátorů jsou však stejné a to je problematika, kterou tato práce popisuje.
17

Dimensionamiento de la capacidad y caracterización de la calidad de una red gprs

Espinoza Armijo, Jaime Ignacio January 2007 (has links)
El objetivo del presente trabjo de título es entender el funcionamiento de una red GPRS, identificando cada uno de sus componentes e interfaces, para luego proponer un modelo teórico simple que permita dimensionar la capacidad y caracterizar la calidad de una red GPRS. El trabajo se enmarca en la iniciativa de la empresa de telefonía celular Movistar Chile, en realizar este en conjunto con el Departamento de Ingeniería Eléctrica de la Universidad de Chile, para sentar las bases de un intercambio de conocimiento tecnológico.
18

Double Differential TOA Positioning for GSM

Nordzell, Andreas January 2013 (has links)
For most time-based positioning techniques, synchronization between the objectsin the system is of great importance. GPS (global positioning system) signalshave been found very useful in this area. However, there are some shortcomingsof these satellite signals, making the system vulnerable. The aim of this masterthesis is to investigate an alternative method for synchronization, independent ofGPS signals, which could be used as a complement. The proposed method takesadvantage of the broadcast signals from telecommunication towers, and use themfor calculation of the synchronization error between two receivers. By looking atthe time difference between arrival times at the receivers, and compare it to thetrue time difference, the synchronization error can be found. A precondition isthat the locations of the receivers as well as the tele tower are known beforehand,so that the true time difference can be calculated using geometry.The arrival times are determined through correlation between the received signalsand known training bits, which are a part of the transmission sequence. Forverification, experiments were made on localization of a mobile phone in theGSM (global system of mobile communications) network.This researchwas a collaboration with FOI, the Swedish Defense Research Agency,where most of the work was done.
19

Choix des produits et concurrence en prix sur le marché français de la téléphonie GSM /

Barberis, Nathalie. January 2000 (has links)
Th. doct.--Économie des systèmes d'information--Paris--ENST, 2000. / En appendice, choix de documents en anglais et en français. Bibliogr. p. 324-335. Résumé en français et en anglais.
20

Méthode de détection et de reconnaissance de bruits électromagnétiques permettant la prédiction de leurs effets sur les transmissions GSM-R / Detection and recognition method of electromagnetic noises allowing the prediction of their impact on GSM-R transmissions

Dudoyer, Stephen 17 September 2013 (has links)
Avec la multiplication des systèmes électroniques analogiques et numériques embarqués dans les moyens de transports actuels, l’environnement électromagnétique (EM) devient de plus en plus riche en signaux de toutes sortes et, donc, il devient plus complexe à caractériser. Dans ces travaux de thèse, nous nous intéressons au GSM-R (Global System for Mobile communications - Railways). Il s’agit du nouveau système de communication radio numérique portant la signalisation actuellement en cours de déploiement sur le réseau ferroviaire européen afin d'assurer l'interopérabilité des TGV. Ainsi, tous les pays d’Europe utiliseront le même système, ce qui facilitera la circulation des trains transfrontaliers d’un pays à l’autre. En environnement ferroviaire, le GSM-R doit faire face à différentes sources de bruit EM, notamment aux perturbations EM transitoires provenant du contact glissant entre la caténaire et le pantographe. Ces perturbations couvrent de larges bandes de fréquences dont, potentiellement, celles du GSM-R. Nous proposons une méthode de classification qui permet de prédire l’effet des perturbations EM transitoires sur la qualité des transmissions GSM-R. Cette méthode de classification pourrait être mise en place à bord des trains où elle permettrait d’identifier et localiser les zones critiques pour la qualité des transmissions GSM-R. Du point de vue de la standardisation, ces travaux de recherche pourraient contribuer à l’évolution nécessaire des équipements et des méthodologies définies dans les normes CEM afin de s’adapter aux nouvelles problématiques émanant de la multiplicité des systèmes et protocoles de communication sans fils employés dans le monde des transports. / With the proliferation of analog and digital electronic systems in the current means of transport, the electromagnetic (EM) environment becomes richer and richer in all kinds of signals and, therefore, it becomes more difficult to characterize.In this thesis, we focus on a particular digital system: the GSM-R (Global System for Mobile communications - Railways). It is the new digital radio communication system under deployment on the European rail network in order to ensure the interoperability of high-speed trains in Europe. Then, all countries in Europe will use the same system, which will facilitate the movement of cross-border trains from a country to another one. In the railway environment, the GSM-R is subject to different EM noise sources, including transient EM interferences coming from the sliding contact between the pantograph and the catenary. These disturbances cover wide frequency bands including, potentially, those of the GSM-R system. We propose a classification method for predicting the effect of transient EM disturbances on the quality of GSM-R transmissions.This classification method could be implemented on trains where it could identify and locate critical areas for the quality of GSM-R transmissions along the journey. From the point of view of standardization, these research works could contribute to the necessary evolution of equipment and methods defined in EMC standards in order to cover the new problems arising from the multiplicity of wireless communication systems and protocols employed nowadays in the world of transports.

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