Network Optimization Algorithm For Fingerpriting Localization Based On Location Privacy Preservation Of Users In Indoor WLAN

With the emergence of new diversified types of mobile devices, as well as the applications of Location Based Services(LBS), location information plays a more and more important role. The location based service consists of mobile terminal, positioning system(locating the user's location), mobile communication network, and service provider. The service flow of it is that, first of all, the mobile terminal gets its location information through the positioning system. Then, the mobile terminal transmits the location information and query content to the location server through the mobile communication network. Finally, the location server returns the results to the mobile terminal. Particularly, when the positioning system uses the WLAN(Wiress Local Area Network) fingerprinting-based localization which based on network terminal positioning model, there are two stages of information leakage, which result in the location of privacy threats. At first stage, when the mobile terminal wants to obtain his location information from the positioning system, he needs to transmit the data which obtained in online stage to the positioning server, and then the information could be attacked. At second stage, when the mobile terminal transmits the location information and query content to the location server through the mobile communication network, it could be attacked which directly causes the location of leakage.In recent years, there are many studies focusing on the user's location privacy protection. However, most of the studies are mainly based on the service stage without taking into account the positioning system in which the user's own position could leak out. Therefore, this thesis mainly focuses on the users' location privacy protection based on the leakage of first stage. The details of research works and innovation are as follows:1. Analyze the part of indoor WLAN fingerprint location system which could easily reveals location information. We classified the location of the privacy attacks: "client" model and "client + network terminal" model. Furthermore, we analyze the leakage of information in two modes, and derive out that user's location information would indirectly be leak out. Meanwhile, we analyse the correlation of the WLAN network optimization and location privacy protection.2. Quantify the user location privacy in WLAN fingerprinting positioning system by using the modified anonymity which improved from the traditional anonymity. Meanwhile, ineffectiveness was used for assessing the performance of location service quality.3. Combining two attacking models and two system indicators, we construct the WLAN network optimization model based on user location privacy protection. In addition, we discuss the related parameters of the optimization model, and analyze the influence of optimization model based on different parameters.4. Using the fast water-filling algorithm and simulated annealing algorithm to solve the optimization model and obtained the final optimal WLAN network scheme. Furthermore, we operate the experiment to verify our approach in location privacy, service quality, and search algorithms.