朱浩華臺灣大學：資訊工程學研究所連矩鋒Lien, Chu-FengChu-FengLien2007-11-262018-07-052007-11-262018-07-052007http://ntur.lib.ntu.edu.tw//handle/246246/53836定位系統已被廣泛地應用在各種服務，一旦系統得知人以及物件的位置，服務的種類將可變地更為個性化，這些與位置相關的服務包括導航、地域性的廣告、後勤服務、庫存管控、以及博物館導覽等等，而用來啟動及推廣這類服務的，會是一套可於任何時刻在室內及室外環境下精準定位人及物件的系統。 為了實際地評估建立一個能廣泛覆蓋室內和室外環境的定位系統的可行性，我們選擇目前相當普及的 GSM 和 Wi-Fi 兩個無線網路，將利用這兩個無線網路所構成的定位系統放置到 Smart phone 和 PDA phone 上實現，並且在室內及室外環境﹝例如：辦公室、都市、校園和郊區﹞根據不同演算法﹝Centroid、Weighted Centroid、及 Fingerprinting﹞比較它們的定位表現。結果顯示基于 GSM 的定位系統的平均定位誤差在室內﹝室外﹞的環境下是11﹝113﹞公尺，基于 Wi-Fi 的定位系統在室內(室外)環境下的平均定位誤差為5﹝29﹞公尺，我們認為以這樣的精準度來建構一個可適用於室內及室外的定位系統是可行的。在實驗的過程中，我們討論遇到的幾個實際問題並且比較每種定位方法的優缺點。 在文章的最後，我們提出結合GSM及Wi-Fi兩種網路的混合式定位系統。Location is considered as one of most widely utilized context information in context-aware computing. Location-aware services leverage the location of people and objects to provide relevant or personalized information and services to users. An enabling tech-nology is a ubiquitous (pervasive) location system that can accurately track positions of people and objects anytime anywhere in both indoor and outdoor environments. Exam-ples of these location-aware services include navigation services, location-based advertisement services, logistical services, inventory control services, museum guide services, etc. To evaluate feasibility of constructing a practical localization system, which can have wide coverage in both the indoor and outdoor environments, we have selected GSM and Wi-Fi based localization systems, implemented them on commercial GSM/Wi-Fi smart phones and PDAs, and compared their performance under different positioning algo-rithms (e.g., centroid, weighted centroid, and fingerprinting) and different indoor/outdoor environments (e.g., offices, urban and rural areas). Results have shown that the average positional accuracy of a GSM based localization in indoor(outdoor) en-vironment is 11(113) meters, and the average positional accuracy of a Wi-Fi based localization system in indoor(outdoor) environment is 5(29) meters. We consider the accuracy feasible and sufficient for an indoor/outdoor localization system. From our deployment experiences, we discuss several practical problems encountered and com-pare the pros and cons of each localization method. Finally, we propose a GSM/Wi-Fi hybrid localization system that combines the advantages of both GSM/Wi-Fi localiza-tion systems.口試委員會審定書……………………… i Acknowledgements……………………… ii 中文摘要………………………………… iv Abstract ……………………………… vi Chapter 1 Introduction 1 1.1 Location System 1 1.2 GSM and Wi-Fi 3 1.3 Research Claim 5 1.4 Thesis Organization 5 Chapter 2 Related Work 7 Chapter 3 Positioning Algorithms 12 3.1 Centroid Algorithm 12 2.2 Weighted Centroid Algorithm 13 2.3 Fingerprinting 14 Chapter 4 Implementation 17 4.1 Mobile Devices 17 4.2 System Architecture 18 4.2 GSM Implementation 20 4.3 Wi-Fi Implementation 21 4.4 Test Environments 22 4.5 Error distance 22 Chapter 5 Experimental Results 24 5.1 Precision and Accuracy 24 5.1.1 Urban Area 24 5.1.2 Rural Area 28 5.1.3 Campus 31 5.1.5 Indoors 34 5.1.6 Beacon numbers vs. Accuracy 36 5.1.7 Discussion 37 5.2 Other evaluation metrics 38 5.3 Practical Issues 40 5.3.1 Limited RSSI sources 41 5.3.2 Resource constraints on mobile devices 42 5.3.3 Training condition 43 5.3.4 Scale of RSSI readings 43 Chapter 6 Hybrid System 45 6.1 Motivation 45 6.2 Hybrid Architecture 46 6.3 Challenges 48 Chapter 7 Conclusion 49 Bibliography 51889679 bytesapplication/pdfen-USGSM定位Wi-Fi定位室內室外定位定位系統比較分析混合式定位系統GSM LocalizationWi-Fi LocalizationLocalization performance comparisonIndoor/outdoor LocalizationHybrid Localization Systemthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/53836/1/ntu-96-P93922007-1.pdf