by Kwan Lawrence Yeung. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 115-[118]). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Cellular Concept --- p.1 / Chapter 1.2 --- Fixed Channel Assignment --- p.2 / Chapter 1.3 --- Dynamic Channel Assignment --- p.2 / Chapter 1.4 --- Performance Evaluation of DC A --- p.3 / Chapter 1.5 --- Han doff Analysis --- p.3 / Chapter 1.6 --- Mobile Location Tracking Strategies --- p.3 / Chapter 1.7 --- QOS Measure --- p.4 / Chapter 1.8 --- Organization of Thesis --- p.4 / Chapter 2 --- Optimization of Channel Assignment I --- p.6 / Chapter 2.1 --- Introduction --- p.6 / Chapter 2.2 --- Generating Compact Patterns --- p.7 / Chapter 2.2.1 --- Regular size cells --- p.7 / Chapter 2.2.2 --- Irregular size cells --- p.7 / Chapter 2.3 --- Nominal Channel Allocation Methods --- p.10 / Chapter 2.3.1 --- Compact pattern allocation --- p.10 / Chapter 2.3.2 --- Greedy allocation --- p.11 / Chapter 2.3.3 --- Hybrid allocation --- p.11 / Chapter 2.3.4 --- The K-Optimal variations --- p.11 / Chapter 2.3.5 --- Backtracking strategies --- p.12 / Chapter 2.4 --- Performance Comparison --- p.12 / Chapter 2.5 --- Conclusions --- p.16 / Chapter 3 --- Optimization of Channel Assignment II --- p.18 / Chapter 3.1 --- Introduction --- p.18 / Chapter 3.2 --- Basic Heuristics --- p.20 / Chapter 3.2.1 --- Two methods for cell ordering --- p.20 / Chapter 3.2.2 --- Two channel assignment strategies --- p.20 / Chapter 3.3 --- Channel Assignments with Cell Re-ordering --- p.21 / Chapter 3.3.1 --- Four channel assignment algorithms --- p.21 / Chapter 3.3.2 --- Complexity --- p.22 / Chapter 3.3.3 --- An example --- p.22 / Chapter 3.4 --- Channel Assignment at Hotspots --- p.23 / Chapter 3.4.1 --- Strategy F vs strategy R --- p.23 / Chapter 3.4.2 --- Strategy FR --- p.24 / Chapter 3.5 --- Numerical Examples --- p.25 / Chapter 3.5.1 --- "Performance of algorithms F/CR,F/DR,R/CR and R/DR" --- p.26 / Chapter 3.5.2 --- Effect of X & Y on performance of algorithms FR/CR & FR/DR --- p.26 / Chapter 3.5.3 --- Performance of algorithms FR/CR & FR/DR --- p.27 / Chapter 3.6 --- Conclusions --- p.27 / Chapter 4 --- Compact Pattern Based DCA --- p.29 / Chapter 4.1 --- Introduction --- p.29 / Chapter 4.2 --- Compact Pattern Channel Assignment --- p.30 / Chapter 4.2.1 --- Data structures --- p.30 / Chapter 4.2.2 --- Two functions --- p.31 / Chapter 4.2.3 --- Two phases --- p.32 / Chapter 4.3 --- Performance Evaluation --- p.33 / Chapter 4.4 --- Conclusions --- p.36 / Chapter 5 --- Cell Group Decoupling Analysis --- p.37 / Chapter 5.1 --- Introduction --- p.37 / Chapter 5.2 --- One-Dimensional Cell Layout --- p.38 / Chapter 5.2.1 --- Problem formulation --- p.38 / Chapter 5.2.2 --- Calculation of blocking probability --- p.39 / Chapter 5.3 --- Two-Dimensional Cell Layout --- p.41 / Chapter 5.3.1 --- Problem formulation --- p.41 / Chapter 5.3.2 --- Calculation of blocking probability --- p.42 / Chapter 5.4 --- Illustrative Examples --- p.42 / Chapter 5.4.1 --- One-dimensional case --- p.42 / Chapter 5.4.2 --- Two-dimensional case --- p.45 / Chapter 5.5 --- Conclusions --- p.45 / Chapter 6 --- Phantom Cell Analysis --- p.49 / Chapter 6.1 --- Introduction --- p.49 / Chapter 6.2 --- Problem Formulation --- p.49 / Chapter 6.3 --- Arrival Rates in Phantom Cells --- p.50 / Chapter 6.4 --- Blocking Probability and Channel Occupancy Distribution --- p.51 / Chapter 6.4.1 --- Derivation of α --- p.51 / Chapter 6.4.2 --- Derivation of Bside --- p.52 / Chapter 6.4.3 --- Derivation of Bopp --- p.53 / Chapter 6.4.4 --- Channel occupancy distribution --- p.54 / Chapter 6.5 --- Numerical Results --- p.55 / Chapter 6.6 --- Conclusions --- p.55 / Chapter 7 --- Performance Analysis of BDCL Strategy --- p.58 / Chapter 7.1 --- Introduction --- p.58 / Chapter 7.2 --- Borrowing with Directional Carrier Locking --- p.58 / Chapter 7.3 --- Cell Group Decoupling Analysis --- p.59 / Chapter 7.3.1 --- Linear cellular systems --- p.59 / Chapter 7.3.2 --- Planar cellular systems --- p.61 / Chapter 7.4 --- Phantom Cell Analysis --- p.61 / Chapter 7.4.1 --- Call arrival rates in phantom cells --- p.62 / Chapter 7.4.2 --- Analytical model --- p.62 / Chapter 7.5 --- Numerical Examples --- p.63 / Chapter 7.5.1 --- Linear cellular system with CGD analysis --- p.63 / Chapter 7.5.2 --- Planar cellular system with CGD analysis --- p.65 / Chapter 7.5.3 --- Planar cellular system with phantom cell analysis --- p.65 / Chapter 7.6 --- Conclusions --- p.68 / Chapter 8 --- Performance Analysis of Directed Retry --- p.69 / Chapter 8.1 --- Introduction --- p.69 / Chapter 8.2 --- Directed Retry Strategy --- p.69 / Chapter 8.3 --- Blocking Performance of Directed Retry --- p.70 / Chapter 8.3.1 --- Analytical model --- p.70 / Chapter 8.3.2 --- Numerical examples --- p.71 / Chapter 8.4 --- HandofF Analysis for Directed Retry --- p.73 / Chapter 8.4.1 --- Analytical model --- p.73 / Chapter 8.4.2 --- Numerical examples --- p.75 / Chapter 8.5 --- Conclusions --- p.77 / Chapter 9 --- Handoff Analysis in a Linear System --- p.79 / Chapter 9.1 --- Introduction --- p.79 / Chapter 9.2 --- Traffic Model --- p.80 / Chapter 9.2.1 --- Call arrival rates --- p.80 / Chapter 9.2.2 --- Channel holding time distribution --- p.81 / Chapter 9.3 --- Analytical Model --- p.81 / Chapter 9.3.1 --- Handoff probability --- p.81 / Chapter 9.3.2 --- Handoff call arrival rate --- p.81 / Chapter 9.3.3 --- Derivation of blocking probability --- p.81 / Chapter 9.3.4 --- Handoff failure probability --- p.82 / Chapter 9.3.5 --- Finding the optimal number of guard channels --- p.83 / Chapter 9.4 --- Numerical Results --- p.83 / Chapter 9.4.1 --- System parameters --- p.83 / Chapter 9.4.2 --- Justifying the analysis --- p.84 / Chapter 9.4.3 --- The effect of the number of guard channels --- p.84 / Chapter 9.5 --- Conclusions --- p.85 / Chapter 10 --- Mobile Location Tracking Strategy --- p.88 / Chapter 10.1 --- Introduction --- p.88 / Chapter 10.2 --- Review of Location Tracking Strategies --- p.89 / Chapter 10.2.1 --- Fixed location area strategy --- p.89 / Chapter 10.2.2 --- Fixed reporting center strategy --- p.89 / Chapter 10.2.3 --- Intelligent paging strategy --- p.89 / Chapter 10.2.4 --- Time-based location area strategy --- p.89 / Chapter 10.2.5 --- Movement-based location area strategy --- p.90 / Chapter 10.2.6 --- Distance-based location area strategy --- p.90 / Chapter 10.3 --- Optimization of Location Area Size --- p.90 / Chapter 10.3.1 --- Location updating rates ´ؤ linear systems --- p.90 / Chapter 10.3.2 --- Location updating rates ´ؤ planar systems --- p.91 / Chapter 10.3.3 --- Optimal location area size ´ؤ linear systems --- p.92 / Chapter 10.3.4 --- Optimal location area size ´ؤ planar systems --- p.92 / Chapter 10.4 --- Comparison of FLA & DBLA Strategies --- p.93 / Chapter 10.5 --- Adaptive Location Tracking Strategy --- p.94 / Chapter 10.5.1 --- Mobility tracking --- p.94 / Chapter 10.5.2 --- Protocols for ALT strategy --- p.94 / Chapter 10.6 --- Numerical Examples --- p.95 / Chapter 10.7 --- Conclusions --- p.97 / Chapter 11 --- A New Quality of Service Measure --- p.99 / Chapter 11.1 --- Introduction --- p.99 / Chapter 11.2 --- QOS Measures --- p.99 / Chapter 11.3 --- An Example --- p.101 / Chapter 11.4 --- Case Studies --- p.101 / Chapter 11.5 --- Conclusions --- p.106 / Chapter 12 --- Discussions & Conclusions --- p.107 / Chapter 12.1 --- Summary of Results --- p.107 / Chapter 12.2 --- Topics for Future Research --- p.108 / Chapter A --- Borrowing with Directional Channel Locking Strategy --- p.110 / Chapter B --- Derivation of p2 --- p.112 / Chapter C --- Publications Derived From This Thesis --- p.114 / Bibliography --- p.115

by Au-Yeung Kiu-Wai, Dai Lu Yan. / Thesis (M.B.A.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaf 58). / ABSTRACT --- p.ii / TABLE OF CONTENTS --- p.iv / LIST OF ILLUSTRATIONS --- p.vi / LIST OF TABLES --- p.vii / CHAPTER / Chapter I --- INTRODUCTION --- p.1 / Background --- p.1 / Definition of Mobile Commerce --- p.2 / Chapter II --- MOBILE COMMERCE MODELS --- p.3 / Chapter III --- MARKET POTENTIAL IN CHINA --- p.8 / Critical Factors in Market Development --- p.8 / Market Potential in China --- p.9 / Chapter IV --- Methodology --- p.16 / Chapter V --- Finding and Analysis --- p.18 / Descriptive Analysis --- p.18 / Correlation and Regression Test --- p.23 / Demography of Interviewees --- p.24 / Chapter VI --- Recommendations --- p.28 / Five Forces Analysis --- p.28 / Strategies for M-commerce --- p.32 / Chapter VII --- Limitation --- p.40 / Chapter VIII --- Conclusion --- p.41 / APPENDIX l-Table --- p.43 / APPENDIX 2- Questionnaire --- p.52 / BIBLIOGRAPHY --- p.58

Chen Chung-Shue. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 100-102). / Abstracts in English and Chinese. / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Evolution to 3G Mobile --- p.2 / Chapter 1.1.1 --- First Generation --- p.2 / Chapter 1.1.2 --- Second Generation --- p.3 / Chapter 1.1.3 --- Third Generation --- p.3 / Chapter 1.2 --- UTRA Framework --- p.5 / Chapter 1.2.1 --- FDD and TDD --- p.6 / Chapter 1.2.2 --- Channel Spreading --- p.6 / Chapter 1.2.3 --- OVSF Code Tree --- p.8 / Chapter 1.3 --- Cellular Concepts --- p.10 / Chapter 1.3.1 --- System Capacity --- p.10 / Chapter 1.3.2 --- Multiple Access --- p.11 / Chapter 1.3.3 --- Resource Management --- p.15 / Chapter 1.4 --- Organization of the Thesis --- p.16 / Chapter 2. --- Analysis on Multi-rate Operations --- p.18 / Chapter 2.1 --- Related Works in Multi-rate Operations --- p.18 / Chapter 2.1.1 --- Variable Spreading Factor --- p.19 / Chapter 2.1.2 --- Data Time-multiplexing --- p.20 / Chapter 2.1.3 --- Multi-carrier Transmission --- p.21 / Chapter 2.1.4 --- Hybrid TDMA/CDMA --- p.23 / Chapter 2.2 --- Problems in Multi-rate Operations --- p.24 / Chapter 2.2.1 --- Conventional CDMA --- p.24 / Chapter 2.2.2 --- Data Time-multiplexing --- p.25 / Chapter 2.2.3 --- MC-CDMA --- p.25 / Chapter 2.2.4 --- TD-CDMA --- p.27 / Chapter 2.3 --- Multi-user multi-rate Operations --- p.28 / Chapter 3. --- Bandwidth Allocation --- p.29 / Chapter 3.1 --- Most Regular Binary Sequence --- p.30 / Chapter 3.1.1 --- Properties of MRBS --- p.31 / Chapter 3.1.2 --- Construction of MRCS --- p.32 / Chapter 3.1.3 --- Zero-one Sequence under MRBS --- p.33 / Chapter 3.2 --- MRBS in TD-CDMA --- p.35 / Chapter 3.2.1 --- Time Slot Optimization --- p.36 / Chapter 3.2.2 --- Sequence Generator --- p.37 / Chapter 3.3 --- Most Regular Code Sequence --- p.38 / Chapter 3.3.1 --- Properties of MRCS --- p.38 / Chapter 3.2.2 --- Construction of MRCS --- p.41 / Chapter 3.3.3 --- Fraction-valued Sequence under MRCS --- p.42 / Chapter 3.3.4 --- LCC and UCC --- p.45 / Chapter 3.4 --- MRCS in WCDMA --- p.46 / Chapter 3.4.1 --- Spreading Factor Optimization --- p.46 / Chapter 3.4.2 --- Code Generator --- p.48 / Chapter 3.4.3 --- Uplink and Downlink --- p.50 / Chapter 4. --- Multi-access Control --- p.52 / Chapter 4.1 --- Conflict and Resolution --- p.53 / Chapter 4.1.1 --- Conflicts in MRBS and MRCS --- p.53 / Chapter 4.1.2 --- Resolution with Buffering --- p.55 / Chapter 4.2 --- MRBS Transmission Scheduling --- p.56 / Chapter 4.2.1 --- Slot Scheduling on MRBS --- p.56 / Chapter 4.2.2 --- Properties of Scheduling Algorithm --- p.59 / Chapter 4.2.3 --- Scheduled MRBS --- p.71 / Chapter 4.3 --- MRCS Transmission Scheduling --- p.73 / Chapter 4.3.1 --- Slot Scheduling on MRCS --- p.73 / Chapter 4.3.2 --- Properties of Scheduling Algorithm --- p.75 / Chapter 4.3.3 --- Scheduled MRBS --- p.76 / Chapter 4.4 --- Performance Evaluation --- p.78 / Chapter 4.4.1 --- Simulation on Algorithm --- p.78 / Chapter 4.4.2 --- Resource Utilization and Delay Bound --- p.79 / Chapter 4.4.3 --- Blocking Model and System Capacity --- p.80 / Chapter 4.4.4 --- Numerical Analysis --- p.86 / Chapter 5. --- Conclusions and Future works --- p.92 / Appendix A --- p.94 / Appendix B --- p.98 / Bibliography --- p.100

Land mobile radio technology (LMR) has existed since the early 1920's. The most visible manifestation of this technology is the handheld VHF/UHF radios also referred to as 'walkie-talkie'. These handheld devices are one of the most ubiquitous forms of radio communication systems. Most of them are designed for transmitting analog voice signals. Due to an increase in the amount of digitized analog signals over the past few years complemented by a need for transmitting pure digital data, there has been a desire to transmit digital data. There are methods which allow the analog radios to transmit digital data without any modifications; however the data rate achievable using these methods is very low. In contrast, the digital variants of these hand-held radios are capable of transmitting digital data at comparatively higher data rates. However they are expensive and require major infrastructure overhauls. In this thesis, a prototype modem was developed which interfaces with an analog radio without any modifications to the radio. Furthermore, the data rates achievable are comparable with those achieved using digital radios. The modem uses Orthogonal Frequency Division Multiplexing (OFDM) technique to generate an audio band signal which is fed to the radio. The OFDM technique used to generate the audio band signal from data bits ensures maximum bandwidth efficiency. The developed modem is capable of communicating over Ethernet connection. It uses a RJ 45 interface to connect to a data source.

Tao Suyi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 51-53). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.2 / Chapter 1.1.1 --- Mobile Phone Applications --- p.3 / Chapter 1.1.2 --- Location Methods --- p.4 / Chapter 1.1.3 --- Location Algorithms --- p.9 / Chapter 1.2 --- AoA Localization --- p.10 / Chapter 1.3 --- The NLOS Problem --- p.11 / Chapter 2 --- AoA Localization --- p.13 / Chapter 2.1 --- Conventional Approach to AoA Localization --- p.14 / Chapter 2.2 --- Least Squares Approach to AoA Localization --- p.16 / Chapter 2.2.1 --- Ordinary Least Squares Approach (OLS) by Pages-Zamora --- p.16 / Chapter 2.2.2 --- The Weighted Least Squares Approach (WLS) --- p.18 / Chapter 2.3 --- Approximate Maximum Likelihood Method (AML) for AoA Localization --- p.19 / Chapter 2.4 --- Simulations --- p.21 / Chapter 3 --- Analysis and Mitigation of NLoS Effects --- p.26 / Chapter 3.1 --- The Non-Line-of-Sight (NLoS) Effects --- p.26 / Chapter 3.2 --- NLoS Mitigation in AoA Localization --- p.27 / Chapter 3.2.1 --- A Selective Model to Suppress NLOS Errors --- p.27 / Chapter 3.2.2 --- Dimension Determination and LOS Identification --- p.29 / Chapter 3.3 --- Simulations --- p.34 / Chapter 3.3.1 --- Experiment 1 --- p.34 / Chapter 3.3.2 --- Experiment 2 --- p.38 / Chapter 4 --- Conclusions and Suggestions for Future Work --- p.42 / Chapter 4.1 --- Conclusions --- p.42 / Chapter 4.2 --- Suggestions for future work --- p.44 / Chapter A --- Derivation of the Cramer Rao Lower Bound (CRLB) for AoA Localization --- p.45 / Chapter A.1 --- CRLB for all LoS --- p.45 / Chapter A.2 --- CRLB for both LoS and NLoS --- p.46 / Chapter B --- Derivation of the Error Covariance for OLS and WLS Estima- tors --- p.48 / Chapter B.1 --- Error Covariance for OLS Estimator --- p.49 / Chapter B.2 --- Error Covariance for WLS Estimator --- p.50 / Bibliography --- p.51

This thesis presents a framework for a platform that integrates various infrastructural services and facilities in an automated manner to improve and coordinate the processes of medical emergency response system (MERS). It aims to improve the quality of healthcare system infrastructure by improving the quality of service of MERS. Presently the processes of MERS and their coordination are semi-automated, which adds to the complication of service availability and information exchange among participating systems, thereby affecting the MERS' quality of service adversely. An integrated platform for the coordination of MERS processes can help improve its quality of service and ensure better control of data and process flow. The improvements to the MERS service quality can significantly contribute to the improvement of the quality of healthcare infrastructure. The integrated platform framework presented here resolves the problems of data flow and process coordination to achieve the desired goal. / by Nabarum Chakrabarty. / Thesis (M.S.C.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

對於無線網絡運營商來說，聯合優化其經濟和技術方面的決策以獲得商業成功正在變得越來越重要。一個運營商的決策可能包括對技術的選取和部署時間的把握、資源投資的數量，以及針對他所提供的服務的定價。考慮到這些決策彼此之間有關聯，我們需要對這些決策進行聯合優化，特別當運營商面對有限的資源、不成熟的技術和市場競爭時，該優化會變得困難。本論文綜合考慮兩類網絡中的這些因素。注意到在所有絨線技術中蜂窩網絡擁有最廣泛的市場佔有率，我們先研究蜂窩網路中的經濟學。然後我們研究認知無線電中的經濟學，考慮到該技術代表了未來無線技術發展的一個主要趨勢。 / 在本論文的第一部分，我們研究一個蜂窩網絡運營商在經濟和技術方面的決策，涉及到網路升級、服務分類和社交應用。首先，我們提出了一套博弈論模型來研究互相競爭的運營商從目前3G 蜂窩技術升級為未來一代(4G) 技術的部署時間。我們的分析指出運營商通常會選擇不同的升級時間以避免激烈的競爭。升級早的運營商在市場佔有方面有優勢，而升級晚的運營商只需承擔少量的升級成本並將面對一個更成熟的4G市場。其次，我們研究一個運營商是否有經濟動機在他已有的蜂窩基站C(macrocell)的基礎上再鋪設家庭基站(femtocell)。家庭基站能解決4G 網絡中室內用戶信號接收差的問題，但是該服務會佔用運營商原本就有限的頻譜資源。最後，我們嘗試去理解一個運營商該如何為異構的智慧手機用戶提供經濟刺激來鼓勵他們協助社交應用(比如，信息收集和分布式計算)的建立。在信息不對稱的情況下，我們設計了有效的激勵機制來根據智慧手機用戶不同的隱私損失、使用能耗和計算效率來提供獎勵。 / 在本論文的第二部分，我們在認知其在線電網絡中研究投資的便利性、頻譜感知的不確定性和安全性將如何影響一個次級(沒有頻譜執照的)運營商的決策。首先，我們研究一個可以通過動態頻譜租賞和頻譜感知兩種靈活方式來獲得絨線頻譜的次級運營商。我們聯合研究該運營商的投資選擇和對底層用戶的定價策略來使其利益最優。與動態頻譜租貸相比，頻譜感知不穩定但是能節約投資成本。其次，我們考慮一個包含兩個運營商的競爭市場，並研究他們之間在投資和定價方面的競爭。我們指出該競爭會給底層用戶帶來顯著好處而給運營商們帶來的收益總損失不會超過25% 。最後，一個運營商可能想利用多用戶合作式頻譜感知技術來提高感知的精確性但是該技術容易遭受數據偽造攻擊(data falsification attacks) 。我們通過合適的攻擊檢測和懲罰設計了有效的機制以防範攻擊。 / It is becoming increasingly important for wireless network operators to jointly optimize economic and technological decisions for business success. An operator's decisions may involve the choices and timings of technology adoptions, the amount of resources to invest, and the prices to set for his services. These decisions are coupled with each other and need to be jointly optimized, and such optimization will be challenging when the operator faces limited resources, immature technology, and market competition. This thesis focuses on such issues in two types of networks. We first study the economics of cellular networks, which have the largest market occupancy among all wireless technologies. We then look at the economics of cognitive radios networks, which represent one of the main development trends for wireless technologies in the near future. / In the first part of this thesis, we study a cellular operator's economic and technological decisions related to network upgrade, service differentiation, and social applications. First, we develop a game theoretic model for studying competitive operators' upgrade timing decisions from the existing 3G cellular technology to the next generation (4G) technology. Our analysis shows that operators often select different upgrade times to avoid severe competition. The operator upgrading earlier has advantage in increasing market share, while the one upgrading later benefit from decreased upgrade cost and a more mature 4G market. Second, we study an operator's economic incentive of deploying femtocell service on top of his existing macrocell service. The femtocell can resolve the issue of poor signal receptions for indoor users in 4G networks, but need to occupy the operator's limited spectrum resources. Finally, we try to understand how an operator can provide economic incentives for the heterogeneous smartphone users to collaborate in social applications (e.g., data acquisition and distributed computing). Under asymmetric information, we design effcient incentive mechanisms that reward smartphone users according to their different sensitivities to privacy loss, energy and computing effciencies. / In the second part of this thesis, we study how investment flexibility, sensing uncertainty, and sensing security in cognitive radio networks affect a secondary (unlicensed) operator's decisions. First, we study a secondary operator, who can flexibly acquire wireless spectrum through both dynamic spectrum leasing and spectrum sensing. We jointly study an operator's investment choices and pricing strategy to the end users to maximize his profit. Compared to spectrum leasing, spectrum sensing is unreliable but has a small cost. Second, we consider a competitive market with two operators, and study their competition in both investment and pricing. We show that end users significantly benefit from such market competition, and the operators' total profit loss due to competition is lower bounded by 25% of the maximum. Finally, an operator may want to deploy collaborative spectrum sensing to improve sensing accuracy, but this approach is vulnerable to data falsification attacks. We design effective attack prevention mechanisms through proper attack detection and punishment. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Duan, Lingjie. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 310-336). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i / Acknowledgement --- p.vi / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Economics of Cellular Networks --- p.3 / Chapter 1.2 --- Economic Viability of Cognitive Radio Networks --- p.5 / Chapter 1.3 --- Outline and Contributions --- p.9 / Chapter I --- Economics of Cellular Networks --- p.13 / Chapter 2 --- Economics of 4G Cellular Network Upgrade --- p.14 / Chapter 2.1 --- Introduction --- p.14 / Chapter 2.1.1 --- Related Work --- p.18 / Chapter 2.2 --- System Model --- p.19 / Chapter 2.2.1 --- Value of Cellular Networks --- p.19 / Chapter 2.2.2 --- User Churn during Upgrade from 3G to 4G Services --- p.23 / Chapter 2.2.3 --- Operators' Revenues and Upgrade Costs --- p.25 / Chapter 2.3 --- 4G Monopoly Market --- p.26 / Chapter 2.4 --- 4G Competition Market: Duopoly Model and Game Formulation --- p.32 / Chapter 2.4.1 --- Operators' Long-term Profits --- p.34 / Chapter 2.4.2 --- Duopoly Upgrade Game --- p.37 / Chapter 2.5 --- 4G Competition Market: No Inter-network switching --- p.39 / Chapter 2.6 --- 4G Competition Market: Practical Inter-network Switching Rate --- p.40 / Chapter 2.7 --- Summary --- p.50 / Chapter 2.8 --- Appendix --- p.50 / Chapter 2.8.1 --- Proof Sketch of Theorem 2 --- p.50 / Chapter 2.8.2 --- Proof Sketch of Theorem 3 --- p.52 / Chapter 3 --- Economics of Femtocell Service Provision --- p.55 / Chapter 3.1 --- Introduction --- p.55 / Chapter 3.1.1 --- Related Work --- p.60 / Chapter 3.2 --- Benchmark: Macrocell Service Only --- p.62 / Chapter 3.2.1 --- Users' Bandwidth Demands in Stage II --- p.63 / Chapter 3.2.2 --- Operator's Pricing in Stage I --- p.65 / Chapter 3.3 --- Provision of Femtocell Service --- p.67 / Chapter 3.3.1 --- Users' Service Choices and Bandwidth Demands in Stage II --- p.71 / Chapter 3.3.2 --- Operator's Spectrum Allocations and Pricing in Stage I --- p.73 / Chapter 3.4 --- Impact of Users' Reservation Payoffs --- p.75 / Chapter 3.5 --- Impact of Femtocell Frequency Reuse --- p.82 / Chapter 3.6 --- Impact of Femtocell Operational Cost --- p.84 / Chapter 3.7 --- Impact of Limited Femtocell Coverage --- p.89 / Chapter 3.8 --- Summary --- p.95 / Chapter 4 --- Smartphone Collaboration on Social Applications --- p.96 / Chapter 4.1 --- Introduction --- p.96 / Chapter 4.1.1 --- Related Work --- p.100 / Chapter 4.2 --- Collaboration on Data Acquisition Application --- p.102 / Chapter 4.2.1 --- System Model of Data Acquisition --- p.102 / Chapter 4.2.2 --- Collaboration under Complete Information --- p.105 / Chapter 4.2.3 --- Collaboration under Symmetrically Incomplete Information --- p.106 / Chapter 4.2.4 --- Collaboration under Asymmetrically Incomplete Information --- p.109 / Chapter 4.3 --- Collaboration on Distributed Computing Application --- p.117 / Chapter 4.3.1 --- System Model on Distributed Computation --- p.117 / Chapter 4.3.2 --- Contractual Interactions between Client and Users --- p.119 / Chapter 4.3.3 --- Contract Design under Complete Information --- p.120 / Chapter 4.3.4 --- Client's Contract Design under Asymmetrically Incomplete Information --- p.123 / Chapter 4.4 --- Summary --- p.133 / Chapter 4.5 --- Appendix --- p.134 / Chapter 4.5.1 --- Discussion of Model (4.2) in Different Information Scenarios --- p.134 / Chapter 4.5.2 --- Proof of Theorem 9 --- p.135 / Chapter 4.5.3 --- Proof of No Collaboration and Pure Strategy NE in Theorem 10 --- p.136 / Chapter 4.5.4 --- Proof of Existence And Uniqueness of Equilibrium Threshold in Theorem 12 --- p.137 / Chapter 4.5.5 --- Proof of Theorem 13 --- p.139 / Chapter 4.5.6 --- Proof of Theorem 14 --- p.141 / Chapter 4.5.7 --- The proof of Proposition 1 --- p.142 / Chapter 4.5.8 --- Approximated Algorithm to Solve Problem (4.23) --- p.146 / Chapter II --- Economics of Cognitive Radio Networks --- p.149 / Chapter 5 --- Monopoly Spectrum Market Using Cognitive Radios --- p.150 / Chapter 5.1 --- Introduction --- p.150 / Chapter 5.1.1 --- Related Work --- p.155 / Chapter 5.2 --- Network Model --- p.157 / Chapter 5.2.1 --- Background on Spectrum Sensing and Leasing --- p.157 / Chapter 5.2.2 --- Notations and Assumptions --- p.159 / Chapter 5.2.3 --- A Stackelberg Game --- p.163 / Chapter 5.3 --- Backward Induction of the Four-stage Game --- p.164 / Chapter 5.3.1 --- Spectrum Allocation in Stage IV --- p.165 / Chapter 5.3.2 --- Optimal Pricing Strategy in Stage III --- p.167 / Chapter 5.3.3 --- Optimal Leasing Strategy in Stage II --- p.171 / Chapter 5.3.4 --- Optimal Sensing Strategy in Stage I --- p.173 / Chapter 5.4 --- Equilibrium Summary and Numerical Results --- p.179 / Chapter 5.4.1 --- Robustness of the Observations --- p.185 / Chapter 5.5 --- The Impact of Spectrum Sensing Uncertainty --- p.187 / Chapter 5.6 --- Learning the Distribution of Sensing Realization Factor α --- p.191 / Chapter 5.6.1 --- Performance Evaluation of Machine Learning --- p.193 / Chapter 5.7 --- Summary --- p.195 / Chapter 5.8 --- Appendix --- p.196 / Chapter 5.8.1 --- Proof of Theorem 18 --- p.196 / Chapter 5.8.2 --- Proof of Theorem 19 --- p.197 / Chapter 5.8.3 --- Supplementary Proof of Theorem 21 --- p.198 / Chapter 6 --- Competitive Spectrum Market Using Cognitive Radios --- p.204 / Chapter 6.1 --- Introduction --- p.204 / Chapter 6.1.1 --- Related Work --- p.209 / Chapter 6.2 --- Network and Game Model --- p.211 / Chapter 6.2.1 --- Users' and Operators' Models --- p.213 / Chapter 6.3 --- Backward Induction of the Three-Stage Game --- p.215 / Chapter 6.3.1 --- Spectrum Allocation in Stage III --- p.217 / Chapter 6.3.2 --- Operators' Pricing Competition in Stage II --- p.221 / Chapter 6.3.3 --- Operators' Leasing Strategies in Stage I --- p.226 / Chapter 6.4 --- Equilibrium Summary --- p.231 / Chapter 6.4.1 --- How Network Dynamics Affect Equilibrium Decisions --- p.234 / Chapter 6.5 --- Equilibrium Analysis under General SNR Regime --- p.237 / Chapter 6.6 --- Impact of Operator Competition --- p.239 / Chapter 6.6.1 --- Maximum Profit in the Coordinated Case --- p.239 / Chapter 6.6.2 --- Impact of Competition on Operators' Profits --- p.242 / Chapter 6.6.3 --- Impact of Competition on Users' Payoffs --- p.244 / Chapter 6.7 --- Summary --- p.245 / Chapter 6.8 --- Appendix --- p.246 / Chapter 6.8.1 --- Proof of Theorem 24 --- p.246 / Chapter 6.8.2 --- Proof of Theorem 25 --- p.250 / Chapter 7 --- Security Protection in Collaborative Spectrum Sensing --- p.256 / Chapter 7.1 --- Introduction --- p.256 / Chapter 7.1.1 --- Related Work --- p.260 / Chapter 7.2 --- Preliminary --- p.261 / Chapter 7.2.1 --- CRN Model and Assumptions --- p.261 / Chapter 7.2.2 --- Spectrum Sensing and Opportunistic Access Model --- p.264 / Chapter 7.2.3 --- Collision Penalty --- p.265 / Chapter 7.2.4 --- Decision Fusion Rule --- p.266 / Chapter 7.3 --- Attackers' Behaviors Without Punishment --- p.268 / Chapter 7.3.1 --- All SUs sense the channel idle --- p.270 / Chapter 7.3.2 --- All honest SUs sense the channel idle, but some attacker(s) senses the channel busy --- p.270 / Chapter 7.3.3 --- Some honest SUs sense the channel busy --- p.272 / Chapter 7.4 --- Attack-Prevention Mechanism: A Direct Punishment --- p.273 / Chapter 7.5 --- Attack-Prevention Mechanism: An Indirect Punishment --- p.277 / Chapter 7.6 --- Summary --- p.286 / Chapter 7.7 --- Appendix --- p.286 / Chapter 7.7.1 --- Relaxation of Assumptions A1 and A3 --- p.286 / Chapter 7.7.2 --- Attack Prevention in Case:AT of Section 7.5 --- p.293 / Chapter 7.7.3 --- Proof of Lemma 6 --- p.297 / Chapter 8 --- Conclusion and Future Work --- p.299 / Chapter 8.1 --- Conclusion --- p.299 / Chapter 8.2 --- Extensions of 4G Network Upgrade in Chapter 2 --- p.302 / Chapter 8.3 --- Extensions of Femtocell Service Provision in Chapter 3 --- p.303 / Chapter 8.4 --- Extensions of Smartphone Collaboration on Social Applications in Chapter 4 --- p.304 / Chapter 8.5 --- Extensions of Monopoly Spectrum Market in Chapter 5 --- p.305 / Chapter 8.6 --- Extensions of Competitive Spectrum Market in Chapter 6 --- p.306 / Chapter 8.7 --- Extensions of Security Protection in Collaborative Spectrum Sensing in Chapter 7 --- p.308 / Bibliography --- p.310

近年來，使用者通過移動數據網路，如3G和LTE，連接到互聯網的數目急劇增加。眾所周知無線網路和移動數據網路展現的特點和有線網路有很大的不同。儘管如此，大多數移動應用程式的基本構建塊，即傳輸控制協議（TCP），在很大程度上仍是根植於有線網路。本論文通過廣泛的開展多個移動數據網路，包括3G，HSPA，最新的LTE網路的測試和實驗，探討TCP在現代移動數據網路的性能。儘管移動數據網路頻寬的迅速增加，我們的測量結果均顯示，現有的TCP實現在實踐中表現不佳，未能利用高速移動數據網路豐富的頻寬。這項工作解決TCP的性能限制，採用一種新的方法透明協議優化，通過在中間網路設備即時優化TCP，顯著提高TCP的吞吐量。具體來說，這項工作發展（一）一個新穎的機會傳輸算法克服TCP的流量控制的瓶頸;（二）一個傳輸速率控制演算法來解決TCP的拥塞控制的瓶頸;（三）一個新穎的投機重傳演算法，以提高TCP在重傳中的吞吐量;（四）用隨機模型來量化TCP吞吐量性能對移動網路資源利用率的影響;（五）一個新的隊列長度測量算法，為擁塞控制和網路監測打開一條新的途徑。另外，擬議的協議優化技術已全面實施，變成一個移動加速器裝置已經成功在三個不同的3G/LTE生產移動數據網路領域試用，實驗顯示TCP的吞吐量從48%增加至163%。在發明一種新的傳輸協議，或修改現有的TCP實施相比，所提出的方法不要求在用戶端/伺服器的主機現有的TCP實施任何修改，不需要重新配置伺服器或用戶端，並因此可以容易在現今的3G和4G移動網路部署，提高所有現有網路上運行在TCP之上的應用程式的吞吐量性能。 / The number of Internet users which are connected via mobile networks such as 3G and LTE has increased dramatically in recent years. It is well-known that wireless networks in general, and mobile data networks in particular, exhibit characteristics that are very different from their wired counterparts. Nevertheless, the fundamental building block of most Internet applications, namely the Transmission Control Protocol (TCP), is still largely rooted in wired networks. This dissertation investigate the performance of TCP over modern mobile data networks through extensive measurements and experiments carried out in multiple production data networks, ranging from 3G, HSPA, to the latest LTE networks. Despite the rapid increases in mobile network bandwidth, our measurements consistently reveal that existing TCP implementations perform sub-optimally in practice, failing to utilize the abundant bandwidth available in high-speed mobile networks. This work tackles the performance limitations of TCP using a novel approach - transparent protocol optimization, to significantly improve TCP’s throughput performance using on-the-fly protocol optimization carried out by an intermediate network device in-between the TCP end-hosts. Specifically, this work develops (i) a novel opportunistic transmission algorithm to overcome the TCP’s flow control bottleneck; (ii) a transmission rate control algorithm to tackle TCP’s congestion control bottleneck; (iii) a new opportunistic retransmission algorithm to improve TCP’s performance during packet loss recovery; (iv) a stochastic model to quantify the impact of TCP throughput performance on mobile network capacity; and (v) a new queue length estimation algorithm which opens a new avenue for congestion control and network monitoring. In addition, the proposed protocol optimization techniques have been fully implemented into a mobile accelerator device which has been successfully field trialed in three different production 3G/LTE mobile networks, consistently increasing TCP’s throughput by 48% to 163%. In contrast to inventing a new transport protocol or modifying an existing TCP implementation, the proposed approach does not require any modification to the existing TCP implementation at the client/server hosts, does not require any reconfiguration of the server or client, and hence can be deployed readily in today’s 3G and 4G mobile networks, raising the throughput performance of all existing network applications running atop TCP. / Detailed summary in vernacular field only. / Liu, Ke. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 166-174). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / Abstract --- p.2 / Acknowledgement --- p.6 / Chapter 1 --- p.1 / Introduction --- p.1 / Chapter 1.1 --- Motivation --- p.1 / Chapter 1.2 --- Contributions --- p.3 / Chapter 1.3 --- Structure of the Thesis --- p.6 / Chapter 2 --- p.9 / Flow and Congestion Control --- p.9 / Chapter 2.1 --- TCP Performance Bottlenecks --- p.9 / Chapter 2.2 --- Background and related works --- p.16 / Chapter 2.3 --- Transparent Protocol Optimization --- p.20 / Chapter 2.3.1 --- Opportunistic Transmission --- p.20 / Chapter 2.3.2 --- Transmission Rate Control --- p.22 / Chapter 2.3.3 --- Lost Packet Recovery --- p.27 / Chapter 2.4 --- Modeling and Analysis --- p.28 / Chapter 2.4.1 --- Background and Assumptions --- p.28 / Chapter 2.4.2 --- Queue Length at the Radio Interface --- p.31 / Chapter 2.4.3 --- Queue Length Bounds --- p.38 / Chapter 2.4.4 --- Guaranteeing Full Bandwidth Utilization --- p.45 / Chapter 2.4.5 --- Link Buffer Size Requirement --- p.47 / Chapter 2.5 --- Performance Evaluation --- p.53 / Chapter 2.5.1 --- Parameter Tuning --- p.53 / Chapter 2.5.2 --- Bandwidth Efficiency --- p.56 / Chapter 3 --- p.62 / Packet Loss Recovery --- p.62 / Chapter 3.1 --- Introduction --- p.62 / Chapter 3.2 --- TCP Loss Recovery Revisited --- p.64 / Chapter 3.2.1 --- Standard TCP Loss Recovery Algorithm --- p.64 / Chapter 3.2.2 --- Loss Recovery Algorithm in Linux --- p.66 / Chapter 3.2.3 --- Loss Recovery Algorithm in A-TCP --- p.67 / Chapter 3.3 --- Efficiency of TCP Loss Recovery Algorithms --- p.68 / Chapter 3.3.1 --- Standard TCP Loss Recovery Algorithm --- p.70 / Chapter 3.3.2 --- TCP Loss Recovery in Linux --- p.72 / Chapter 3.3.3 --- Loss Recovery Algorithm Used in A-TCP --- p.72 / Chapter 3.3.4 --- Discussions --- p.73 / Chapter 3.4 --- Opportunistic Retransmission --- p.74 / Chapter 3.4.1 --- Applications and Performance Analysis --- p.76 / Chapter 3.4.2 --- Bandwidth Utilization During Loss Recovery --- p.78 / Chapter 3.5 --- Experimental Results --- p.81 / Chapter 3.5.1 --- Model Validation --- p.85 / Chapter 3.5.2 --- Impact of Loss Recovery Phase on TCP Throughput --- p.85 / Chapter 3.5.3 --- A-TCP with Opportunistic Retransmission --- p.86 / Chapter 3.6 --- Summary --- p.87 / Chapter 4 --- p.89 / Impact on Mobile Network Capacity --- p.89 / Chapter 4.1 --- Introduction --- p.89 / Chapter 4.2 --- Background and Related Work --- p.91 / Chapter 4.2.1 --- TCP Performance over Mobile Data Networks --- p.91 / Chapter 4.2.2 --- Modeling of Mobile Data Networks --- p.92 / Chapter 4.3 --- System Model --- p.94 / Chapter 4.3.1 --- Mobile Cell Bandwidth Allocation --- p.95 / Chapter 4.3.2 --- Markov Chain Model --- p.96 / Chapter 4.3.3 --- Performance Metric for Mobile Internet --- p.98 / Chapter 4.3.4 --- Protocol-limited Capacity Loss --- p.100 / Chapter 4.3.5 --- Channel-limited Capacity Loss --- p.101 / Chapter 4.4 --- Performance Evaluation --- p.102 / Chapter 4.4.1 --- Service Response Time --- p.103 / Chapter 4.4.2 --- Network Capacity Loss --- p.105 / Chapter 5 --- p.114 / Mobile Link Queue Length Estimation --- p.114 / Chapter 5.1 --- Introduction --- p.115 / Chapter 5.2 --- Sum-of-Delay (SoD) algorithm Revisited --- p.117 / Chapter 5.2.1 --- Queue Length and Link Buffer Size Estimation --- p.117 / Chapter 5.2.2 --- A Bound on Estimation Error --- p.120 / Chapter 5.2.3 --- Impact of Uplink Delay Variations --- p.122 / Chapter 5.3 --- Uplink Delay Variation Compensation --- p.127 / Chapter 5.3.1 --- Exploiting the TCP Timestamp Option --- p.127 / Chapter 5.3.2 --- TCP Timestamp Granularity --- p.130 / Chapter 5.4 --- Performance Evaluation --- p.131 / Chapter 5.4.1 --- Link buffer size estimation under uplink delay variations --- p.132 / Chapter 5.4.2 --- Queue length estimation under uplink delay variations --- p.136 / Chapter 5.5 --- Summary --- p.136 / Chapter 6 --- p.139 / Summary and Future Works --- p.139 / Chapter 6.1 --- Transparent Protocol Optimization --- p.139 / Chapter 6.2 --- Cross-Layer Modeling and Optimization of Mobile Networks --- p.141 / Chapter Appendix A. --- Derivation of Equations (2.24) and (2.25) --- p.143 / Chapter Appendix B. --- Proof of Theorem 2.1 --- p.145 / Chapter Appendix C. --- for Proof of Theorem 2.2 --- p.147 / Chapter Appendix D. --- for Proof of Theorem 2.3 --- p.150 / Chapter Appendix E. --- for Proof of Theorem 2.4 --- p.151 / Chapter Appendix F. --- for Proof of Theorem 2.5 --- p.152 / Chapter Appendix G. --- for Proof of Theorem 2.6 --- p.153 / Chapter Appendix H. --- for Proof of Theorem 2.7 --- p.156 / Chapter Appendix I. --- for Proof of Theorem 2.8 --- p.157 / Chapter Appendix J. --- for Proof of Theorem 3.2 --- p.161 / Chapter Appendix K. --- for Theorem 3.4 --- p.163 / Chapter Appendix H. --- for Theorem 3.5 --- p.164 / Bibliography --- p.166

In this thesis, we first investigate how to improve user experience of browsing large photos on mobile devices. Currently, the predominant methods for accessing large photos on small devices are down-sampling or manual browsing by zooming and scrolling. Image down-sampling or thumbnail view results in significant information loss due to the excessive resolution reduction. Manual browsing can avoid information loss but it is often time-consuming for users to catch the most crucial information of an image. Employing the concept of information asymmetry, the thesis investigates an image attention model and its extensions under different application scenarios. The image attention model can successfully solve the small screen browsing problem. First of all, different parts of an image contain different information, computer vision technology can analysis image and extract the attention objects to build the image attention model. Secondly, browsing large photo on small display can be formulated as a problem of optimized manipulating of attention objects to improve viewer's browsing experience, which brings about new functions such as automatic browsing and interactive browsing. Thirdly, the screen limitations of the mobile devices will force users to scroll and zoom while browsing images, which can be regarded as direct indications for users' attention, therefore new attention objects can be discovered by analyzing the past browsing log. Lastly, since psycho-physiological research tells us that the importance of an attention object may vary with the users' preferences and tasks, so attention model should also be adaptive to the users' interest. / The thesis also investigates the problem on how to improve the usability of the current image search engines, that is, how to explore the image search results on desktop PCs and mobile devices in a more effective way. The research results show that unsupervised learning technology can help improve the browsing efficiency. The similarity-based presentation method and clustering-base method are better for desktop PC platform and mobile platform respectively. The navigation operations are re-designed to make the new interface easy to use. Based on these results, the thesis also tries to investigate the problem on how to incorporate users' interaction in content-based image retrieval relevance feedback process. The new approach employs the parameter embedding visualization, multi-classifier learning and fusion methods to provide a seamless integrated browsing, user feedback and classifier learning process. (Abstract shortened by UMI.) / Liu Hao. / "July 2005." / Adviser: Xiaoou Tang. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3907. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 107-115). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

Leung Cheung-chi. / "July 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 77-81). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.