[pt] Neste trabalho, foca-se em uma solução alternativa para se expressar a incerteza de medição que é aplicada na localização por identificação por rádio-frequência (RFID). Elabora-se um modelo para a expressão da incerteza de medição, incerteza máxima possível diferencial (IMPD), que aplica-se aos métodos de identificação de células (Cell-Id ou Cid), vizinho mais próximo (VMP) e trilateração (3L) e que possa servir de auxílio à escolha dos parâmetros relevantes para localização, antes da implementação. Propõe-se uma modificação da Cell-ID, denominada Cell-ID média (MCid), e constrói-se o modelo de incertezas tanto para a Cid quanto para a MCid, levando em conta os parâmetros não considerados no modelo da literatura. Os modelos propostos neste trabalho levam, naturalmente, à definição de um alcance ótimo para as tags. Consequentemente, derivam-se fórmulas fechadas para a sua determinação direta e rápida. Com todo o ferramental construído, desenvolveu-se um experimento numérico aplicado à localização de chamadas de emergência segundo critérios do E911, cujos resultados indicaram a possibilidade de localização com a metodologia proposta, ainda que o alcance varie de 40 m em magnitude, em relação ao alcance esférico geralmente adotado na literatura. Mostrou-se como modelar a incerteza dos métodos VMP e 3L e também se comparou a incerteza de medição determinada pelo método proposto neste trabalho com a determinada tanto por simulação de Monte Carlo quanto pela lei de propagação de incertezas. Os resultados indicaram que o método proposto pode estimar a incerteza para altas probabilidades de abrangência, sendo especialmente útil quando nem todas as grandezas de entrada podem ser medidas. / [en] In this work, the focus is on an alternative solution for expressing the uncertainty of a measurement, which is applied in location by the identification through radio-frequency (RFID). A proposal of a model for the expression of measurement uncertainty is presented, named as the maximum possible differential uncertainty (IMPD, in Portuguese), and its application to the Cell-Id (Cid), nearest neighbor (VMP, in Portuguese) and trilateration (3L) methods that may be of use for choosing the relevant parameters for location before implementation. A modification of Cell-ID is proposed, named mean Cell-ID (MCid), and built the error model for both Cid and MCid, taking into account the parameters not considered in the literature. The models proposed in this work conducted, naturally, to the definition of an optimal range for the tags. Consequently, it is derived closed formulae for its direct and fast determination. Finally, with all the tools built, a numerical experiment applied to the location of emergency calls is developed, according to criteria for the E911 (Enhanced 911). The results indicated the possibility of positioning, even if the range shows variations of 40 m, in magnitude, in relation to the spherical range generally adopted in the literature. It was shown how to model the uncertainty of VMP and 3L, and performed a comparison between the measurement uncertainty as given by the method proposed in this work with the one determined by a Monte Carlo simulation. The results indicate that the proposed approach can estimate the measurement uncertainty for high coverage probabilities, and that it is especially useful when one or more input quantities cannot be measured.

No description available.

Today, positioning with GPS and the advantages this entails are almost infinitive, which means that the technology can be utilized in a variety of applications. Unfortunately, there exists a lot of limitations in conjunction with the signals from the GPS can’t reach inside e.g. buildings or underground. This means that an alternative solution that works indoors needs to be developed. The report presents the four most common radio-based technologies, Bluetooth,Wi-Fi, UWB and RFID, which can be used to determine a position. These all have different advantages in cost, accuracy and latency, which means that there exist a number of different applications. The radio-based methods use the measurement techniques, RSSI, TOA, TDOA, Cell-ID, PD or AOA to gather data. The choice of measurement technique is mainly dependent of which radio-based method being used, since their accuracy depends on the quality of the measurements and the size of the detection area, which means that all measurement techniques have different advantages and disadvantages. The measurement data is processed with one of the positioning methods, LS, NLS, ML, Cell-ID, WC or FP, to estimate a position. The choice of positioning method also depends on the quality of the measurements in combination with the size of the detection area. To evaluate the different radio-based methods together with measurement techniques and positioning methods, accuracy, latency and cost are being compared. This is used as the basis for the choice of positioning method, since a general solution can get summarized by finding the least expensive approach which can estimate an unknown position with sufficiently high accuracy.

The aim of the master’s thesis was to implement in the C++ language a software solution of the localization of the mobile phone with Symbian OS in the GSM network. The intended purpose of this solution would be especially the phone localization in the case of its theft or loss. A familiarization with the development process of the Symbian platform and understanding the features of the Symbian version of the C++ language preceded the realization itself, because the Symbian C++ has an original style of the memory manipulation and error handling. The Symbian C++ basic principles and its features used in the implemented software are described in the second chapter of the text part, the first chapter deals with the history and version structuring of the Symbian OS. In the third part of the text is described the created software. The realized solution consists of three parts – server application PhoneLocServer for a mobile device, client application PhoneLocClient for a PC and the web-located part. The server was developed for the Symbian OS in the C++ language in the IDE Carbide.c++ and was tested in the S60 3rd edition SDK MR emulator and on the real device Nokia N73. It is a GUI-less application running in the background, which is run automatically after a smartphone start-up. It controls the incoming SMS over the socket listening and the messages addressed to itself processes before a user can notice them. The control messages body is comprised of a prefix, which identifies them, a password, a sending period value and a state to which application should change. After the receiving of the control SMS server verifies the SMS sender through the use of his telephone number and the password. It compares these values with the data stored for the given IMEI on the web server. If the verification succeeds, the server runs a timer with the period known from the control SMS and on the callback of this timer are transferred the data describing current phone location and state via HTTP protocol to the web server. The GSM localization method “Cell ID” is used for the location determination. After the client user asks for the start of loading the data, he must answer the password and the observed phone’s IMEI and he is verified through the use of the web server again. If the verification succeeds, the periodic download of the server data starts and from the first downloaded file is found out the upload period. Download then continues till the time the client detects the end of sending by the server part or till the client user stops the download himself. The client was developed in the C++ language in the C++ Builder environment. It requires a Windows OS and internet connection for its right function. The web server mediates communication between the server and the client, stores the data for user verification and makes possible the server-side upload by the help of a simple PHP script. In all the used web server directories is present the .htaccess file to improve its security, e.g. it denies the directory listing in a web browser.

In LTE networks, there are several properties that need to be carefully planned for thenetwork to be well performing. As the networks’ traffic increases and the networks aregetting denser, this planning gets even more important. The Physical Cell Id (PCI) is theidentifier of a network cell in the physical layer. This property is limited to 504 values, andtherefore needs to be reused in the network. If the PCI assignment is poorly planned, therisk for network conflicts is high. In this work, the aim is to develop a distributed approach where the planning is performedby the cells involved in the specific conflict. Initially, the PCI allocation problem isformulated mathematically and is proven to be NP-complete by a reduction to the vertexcolouring problem. Two optimisation models are developed which are minimising thenumber of PCI changes and the number of PCIs used within the network respectively. An approach is developed which enlargers the traditional decision basis for a distributedapproach by letting the confused cell request neighbour information from its confusioncausingneighbours. The approach is complemented with several decision rules for theconfused cell to be able to make an as good decision as possible and by that mimic the behaviourof the optimisation models. Three different algorithms are implemented using theapproach as a basis. For evaluation purpose, two additional algorithms are implemented,one which is applicable to today’s standard and one inspired by the work by Amirijoo et al. The algorithms were tested against three different test scenarios where the PCI rangewas narrowed, the number of cells was increased and the network was extended. Thealgorithms were also tested on a small world network. The testing showed promisingresults for the approach, especially for larger and denser networks.