For the mass demands of wireless communication services, the mobile location technologies have drawn much attention of the governments, academia, and industries around the world. In wireless communication, one of the main problems with accurate location is nonline of sight (NLoS) propagation. To solve the problem, we present a new location algorithm with clustering technology by utilizing the geometrical feature of cell layout, time of arrival (ToA) range measurements, and three base stations. The mobile location is estimated by solving the optimal solution of the objective function based on the high density cluster. Simulations study was conducted to evaluate the performance of the algorithm for different NLoS error distributions and various upper bound of NLoS error. The results of our experiments demonstrate that the proposed algorithm is significantly more effective in location accuracy than range scaling algorithm, linear lines of position algorithm, and Taylor series algorithm, and also satisfies the location accuracy demand of E-911.

People value their privacy; however, they typically do not make the protection of their privacy a priority. Privacy is oftentimes not tangible, complicating the efforts of technology users to express and act according to their privacy needs. Additionally, people may not be fully aware of the risks they are subjecting themselves to once they use the Internet for financial transactions, or create profiles on online social networks. Companies post privacy policies inform people about their informational practices; but, this information is extremely difficult to use and typically not considered in users’ decision-making processes. Privacy concerns have also had an impact on users’ adoption of new technologies that share personal information. A plethora of mobile location-finding technologies applications have become available over the last two decades, but the products and services offered by the technology developers may not comprehensively address the privacy implications and privacy concerns surrounding their use. The design considerations for these products may not provide the necessarily amount of control or risk mitigation for users to ensure that their location information is not misused. In this thesis, I focus on the impact of salient privacy information on privacy concerns and behavior in two contexts: online shopping and the use of a mobile-location sharing technology. I examine several case studies focusing on the evolution of privacy attitudes after people use specific technologies. Based on the examination of the use of a location-sharing system, I highlight several design considerations for mobile-location application developers to ensure they address their users privacy concerns. I use the results of online surveys and user studies to provide concrete information on the impact of feedback on the comfort with using location-sharing technology. This research shows that users will pay a premium to purchase from websites that offer better privacy policies IF that privacy information is made visible and understandable. This research points to the importance of control in the management of privacy concerns. Whether it be mandated by legislation, or recommended in industry standards or design standards, offering users control in the form of understandable privacy policy information, or control over the disclosure of personal information by technology, is essential.

[pt] Por anos, o tema da localização de terminais móveis são estudados. Inicialmente de caráter militar, tais estudos já são de grande interesse da sociedade civil. Com o crescimento explosivo do tráfego gerado pelo uso da telefonia móvel, os sistemas de localização tornam-se um forte chamariz de renda das empresas de telefonia móvel. Vários podem ser os serviços baseados em localização, entretanto, dentre eles, os chamados serviços de emergência, tem sido fonte de grande debate internacional. Isto porque, na década passada,os Estados Unidos, através de seu órgão regulador, fixou prazos para que operadoras de telefonia móvel naquele país fossem capazes de obter, com uma certa precisão, a localização de chamadas de emergência, o chamado E911. Contudo, para tal, existem vários modos e técnicas de obtenção da localização, das quais destacam-se as técnicas baseadas em diferença de tempos de chegada, do inglês Time Diference of Arrival - TDoA-. Técnicas estas baseadas na solução de equações hiperbólicas para ofertarem a localização de uma dada estação móvel. Daí, sistemas baseados em TDoA serem também chamados de Sistemas Hiperbólicos. Apegando-se a tais fatos, este estudo explora o tema no intuito de implementar um novo método para a solução de sistemas hiperbólicos de localização. Tal método é caracterizado pela otimização nas medidas de diferenças de tempos de chegada estimadas pelo sistema, que através desta otimização fornecem a localização da estação móvel com uma considerável precisão. / [en] The issue about Mobile Location Systems have been studied for a long time.At first, it was circumscribed to the militar area, but nowadays it has been spread along civil society needs. Due to the boom of the cellular mobile technology, location system may become necessary for the cellular mobile company. Location based services may vary. However, the emergency calls service have been discussed by international companies. This has happened because, last decade, the United States has obliged the wireless carriers to locate accurately emergency calls accurately, called E911. But, for this do happen, there are several ways and techniques to get accuracy location,among which we can highlight time diference of arrival -TDOA-. These techniques are based on hiperbolic equations solutions that offer the location of a mobile. This is why the systems based on TDOA are called Hiperbolic Systems. This dissertation has tried develop new analysis for the hiperbolic system of location. This dissertation is marked by optimization of the TDOA measures, which may offer accuracy location of the station mobile.

[pt] Este trabalho é um estudo sobre radio-localização de terminais móveis em sistemas de tecnologia TDMA. Pela legislação americana e também pela extrema competitividade entre operadores de telefonia na conquista de novos mercados e de provisão de novos serviços, técnicas que permitam a localização do terminal móvel têm sido intensamente pesquisadas. Uma dessas técnicas usa o tempo de chegada (TOA) para estimar a posição do móvel. Como não se tem acesso à medida original de TOA, deve-se estimar TOA a partir de TA (Timing Advance). O valor de TA é enviado pela ERB a EM por meio de um canal de sinalização, que é designado a partir de um conjunto finito de valores discretos que permite que se extraia contornos circulares em torno de cada antena de recepção, a posição do móvel é melhor na interseção de todos aqueles contornos estimados. O erro resultante na estimação do TOA pode ser grande pela ação do erro aleatório e se o TA errado for selecionado. Dado que se sabe somente o TA, o problema é encontrar um estimador e seu erro para o TOA real. Embora a literatura cite diversos processos para solução desse problema, a título de distinguir entre estes e o aqui proposto, denominaremos o processo aqui discutido de Refinamento Sucessivo da Incerteza. / [en] This work is a study about radiolocation of mobile terminals in TDMA systems. In agreement with the American legislation and also because of the extreme competitiveness among wireless operators in order to conquer new markets and provision new services, techniques that allow the localization of the mobile terminal have been intensely researched. One of these techniques uses time of arrival (TOA) to estimate the mobile position. Since the original TOA measurement is not accessible, TOA should be estimated from TA (Timing Advance). The value of TA is sent by the BTS to the MS by means of a signaling channel, which is assigned from a set of discrete values that allows one to draw circular contours around each receiving antenna, the location of the mobile is the best intersection of all those estimated contours. The resultant error in estimated TOA might be large by random error and if the wrong TA will be selected. Given that only TA is know, the problem is to find an estimator and its error for the actual TOA. Although literature mentions diverse processes to solve this problem, in order to distinguish between these and the considered here, we will call the process discussed here of Successive Refinement of the Uncertainty.

This thesis is concerned with the problem of designing Mobile Location Services (MLS) - also commonly termed Location-Based Services - that meet user needs. MLS are applications that users access via a portable device such as a mobile phone. They provide services (i.e. information or other functionality) to end-users based on knowledge of the location of individuals and other entities within the environment. The market failure of many mobile services, including MLS, has been attributed in part to failing to provide `value' to the end user. This thesis reviews different theoretical approaches to help understand the notion of `value', and how value may be used to inform design (Chapter 2). Research methods are also discussed, including the particular challenges with doing `mobile' research (Chapter 3). A survey of UK consumers( Chapter4 ) demonstratesa current lack of use, and lack of awarenesso f most forms of MLS in the UK. llowever, overall positive attitudes,a nd a range of behavioural and demographic data, suggest that MLS have the potential to be successful if they can be designed to meet user needs. A qualitative study of users' travelling behaviour (Chapter 5) then demonstrates how effective mobile information delivery can provide considerable value within a dynamic, uncertain and location-varying environment. This added value is highly dependent on contextual and situated factors, including existing information sources, variances in possible outcomes and the intrinsic qualities of information provision. The thesis then focuses on a particular application domain for MLS - drivers navigating in an unfamiliar environment. A literature review (Chapter 6) investigates how drivers navigate, and what their information needs are. Three experimental studies (Chapters 7 to 9) then investigate what information adds value within a navigation context, the impact of contextual influences on driving and navigation performance, and the impact of the quality of the navigation cue on task performance. Good landmarks (such as traffic lights) are shown to add value for drivers navigating an unfamiliar route, depending on the context at particular manoeuvres. This thesis discusses( Chapter 10) how a multi-disciplinary perspectivec an help maximise the acceptance and effectiveness of MLS. 'Value' can be used to design specific services for users, based on offering new freedoms to the individual within a mobile context, employing time and location sensitivity to maximise relevance, taking into account user knowledge, existing information sources and contextual factors, and ensuring impact on real-world outcomes. In conclusion (Chapter 11), specific contributions and avenues for future work are highlighted.