However, applying directional antennas to wireless networks can also cause new collisions, such as the new hidden terminal problem and the deafness problem. We study the challenges in the MAC layer design with directional antennas and present the state of the art of current MAC protocols with directional antennas. Then, we propose a novel collision avoidance scheme in terms of BT-DMAC (Busy-Tone based Directional Medium Access Control) to address the new collisions with directional antennas. Both the analytical and simulation results show that transmitting busy tones on a different channel can effectively reduce the hidden nodes and mitigate the deafness problem. Thus, integrating multiple channels with directional antennas can bring numerous benefits. Furthermore, we also explore some techniques in the MAC layer design with directional antennas. Some useful insights are also given. / The capacity of wireless networks are mainly affected by two key factors: the interference among concurrent transmissions and the number of simultaneous transmissions on a single interface. Recent studies have found that, using multiple channels can separate concurrent transmissions and significantly improve network throughput. However, those studies only consider wireless nodes that are only equipped with omni-directional antennas, which cause high collisions. On the other hand, some researchers have found that directional antennas bring more benefits such as the reduced interference and the increased spatial reuse compared with omni-directional antennas. But, they only focused on a single-channel network which only allows finite concurrent transmissions. In this thesis, we propose a novel network architecture, in terms of multi-channel networks using multiple directional antennas ( MC-MDA), which integrates the two technologies of multiple channels and directional antennas together and potentially brings more benefits. / We study the capacity of MC-MDA networks and explore the benefits of such networks. We have found that using directional antennas in multi-channel networks can greatly increase the network capacity. Furthermore, such networks require fewer channels than multi-channels with omni-directional antennas. More specifically, we study the channel assignment problem of such MC-MDA networks. Our results indicate that using directional antennas in wireless networks can significantly reduce the required number of channels. Directional antennas have a better spectrum reuse than omni-directional antennas. / Dai, Hongning. / Adviser: Kam-Wing Ng. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3596. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 173-183). / 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. / Abstracts in English and Chinese. / School code: 1307.

Tse Yiu Keung. / Bibliography: leaves 74-75 / Thesis (M.Ph.)--Chinese University of Hong Kong, 1984

by Hung Cheung Kwok. / Thesis (M.S.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves [34]). / ACKNOWLEDGEMENTS / ABSTRACT / TABLE OF CONTENTS / Chapter 1. --- INTRODUCTION --- p.3 / Chapter 1.1 --- PROVISION OF NETWORK SERVICES --- p.3 / Chapter 1.2 --- THE CURRENT ENVIRONMENT FOR SERVICE PROVISION --- p.3 / Chapter 1.3 --- THE COMING ENVIRONMENT FOR SERVICE PROVISION --- p.6 / Chapter 1.4 --- THE ROLE OF THE ASSISTANT SYSTEM --- p.8 / Chapter 1.5 --- OVERVIEW OF THE THESIS --- p.10 / Chapter 2 . --- OVERALL DESIGN --- p.12 / Chapter 2.1 --- INFERENCE ENGINE --- p.14 / Chapter 2 .2 --- KNOWLEDGE BASES --- p.14 / Chapter 2.3 --- COMMAND GENERATOR --- p.15 / Chapter 2.4 --- USER INTERFACE --- p.16 / Chapter 2.5 --- HOST INTERFACE --- p.16 / Chapter 3 . --- KNOWLEDGE BASE DESIGN --- p.18 / Chapter 4. --- INFERENCE ENGINE DESIGN --- p.21 / Chapter 5. --- IMPLEMENTATION --- p.24 / Chapter 5.1 --- SYSTEM DESIGN --- p.24 / Chapter 5.2 --- KNOWLEDGE BASE MAINTENANCE --- p.24 / Chapter 5.3 --- MANUAL MODE --- p.26 / Chapter 5.4 --- AUTOMATIC MODE --- p.27 / Chapter 5.5 --- INTERFACE FUNCTIONS --- p.29 / Chapter 6. --- CONCLUSIONS --- p.31 / REFERENCES / LIST OF FIGURES / Chapter F1. --- THE SCHEMATICS OF THE INTELLIGENT SYSTEM / LIST OF TABLES / Chapter T1. --- STRUCTURE OF SERVICE INFORMATION FILE (SIF) / Chapter T2. --- STRUCTURE OF WORK CODE FILE (WCF) / Chapter T3. --- STRUCTURE OF MAPPING FILE (SIF-PRF´ØMAP) / Chapter T4. --- DATABASE RECORDS OF SIF一PRF.MAP / APPENDICES / Chapter A1. --- KNOWLEDGE BASE LIST FOR FEATURE ANALYSIS (CHK_SIF) / Chapter A2. --- KNOWLEDGE BASE LIST FOR WORK CODE INTERPRETATION (CHK一WCF) / Chapter A3. --- KNOWLEDGE BASE LIST FOR FILE SENDING MONITORING (CHK 一SND) / Chapter A4. --- A SAMPLE RUN OF THE SYSTEM

by Cheung Kam Wah. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 62-63). / Chapter Chapter 1. --- Introduction --- p.1 / Chapter Chapter 2. --- ISDN Architecture --- p.4 / Chapter 2.1 --- ISDN Definition --- p.4 / Chapter 2.2 --- Channel Structure --- p.6 / Chapter 2.3 --- Wiring Configuration of ISDN User-Network Interface --- p.6 / Chapter 2.4 --- ISDN Signalling Protocol at S/T Interface --- p.7 / Chapter Chapter 3. --- ISDN Signalling Protocol Enhancement --- p.8 / Chapter 3.1 --- ISDN Basic Rate Access Configuration --- p.8 / Chapter 3.2 --- Protocol Enhancement --- p.10 / Chapter 3.3 --- ISDN Layer 1 Signalling Protocol Enhancement --- p.11 / Chapter 3.4 --- ISDN Layer 2 Signalling Protocol Enhancement --- p.13 / Chapter 3.5 --- ISDN Layer 3 Signalling Protocol Enhancement --- p.15 / Chapter Chapter 4. --- Basic Call Control Procedure for Special Terminal Equipment --- p.18 / Chapter 4.1 --- Signalling Procedure for Call establishment and Termination --- p.18 / Chapter 4.2 --- Requirements on the Developed System --- p.27 / Chapter Chapter 5. --- Software Simulation --- p.29 / Chapter Chapter 6. --- System Performance Analysis --- p.33 / Chapter 6.1 --- Simple Measurement on the Execution Time of ISDN Call --- p.33 / Chapter 6.2 --- Call Handling Capacity Analysis --- p.36 / Chapter 6.3 --- Call Request Delay Analysis --- p.42 / Chapter Chapter 7. --- Conclusion --- p.59 / References --- p.62 / Appendix I: Software Simulation Program Flowchart --- p.64 / Appendix II: Software Simulation Program in Borland C++ Language --- p.86

Wing-Chung Chan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 81-85). / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Multiresolution Signal Decomposition --- p.5 / Chapter 2.1 --- Introduction --- p.5 / Chapter 2.2 --- Laplacian Pyramid --- p.6 / Chapter 2.2.1 --- Gaussian Pyramid Generation --- p.7 / Chapter 2.2.2 --- Laplacian Pyramid Generation --- p.7 / Chapter 2.2.3 --- Decoding --- p.8 / Chapter 2.2.4 --- Limitation --- p.9 / Chapter 2.3 --- Multiresolution Transform --- p.9 / Chapter 2.3.1 --- Multiresolution Approximation of L2(R) --- p.9 / Chapter 2.3.2 --- Implementation of a Multiresolution Transform --- p.12 / Chapter 2.3.3 --- Orthogonal Wavelet Representation --- p.16 / Chapter 2.3.4 --- Implementation of an Orthogonal Wavelet Representation --- p.18 / Chapter 2.3.5 --- Signal Reconstruction --- p.21 / Chapter 3 --- Multiresolution Learning Method --- p.23 / Chapter 3.1 --- Introduction --- p.23 / Chapter 3.2 --- Input Vector Representation --- p.24 / Chapter 3.2.1 --- Representation at the resolution 1 --- p.24 / Chapter 3.2.2 --- Representation at the resolution 2j --- p.25 / Chapter 3.2.3 --- Border Problem --- p.26 / Chapter 3.3 --- Back-Propagation Network Architecture --- p.26 / Chapter 3.4 --- Training Procedure Strategy --- p.27 / Chapter 3.4.1 --- Sum Squared Error (SSE) --- p.28 / Chapter 3.4.2 --- Intermediate Stopping Criteria --- p.30 / Chapter 3.5 --- Connection Weight Transformation --- p.31 / Chapter 3.5.1 --- Weights between the Input and Hidden Layers --- p.31 / Chapter 3.5.2 --- Weights between the Hidden and Output Layers --- p.33 / Chapter 4 --- Simulations --- p.36 / Chapter 4.1 --- Introduction --- p.36 / Chapter 4.2 --- Choices of the Impulse Response h(n) --- p.36 / Chapter 4.3 --- XOR Problem --- p.39 / Chapter 4.3.1 --- Setting of Experiments --- p.39 / Chapter 4.3.2 --- Experimental Results --- p.41 / Chapter 4.4 --- Numeric Recognition Problem --- p.50 / Chapter 4.4.1 --- Setting of Experiments --- p.50 / Chapter 4.4.2 --- Experimental Results --- p.52 / Chapter 4.5 --- Discussions --- p.72 / Chapter 5 --- Conclusions --- p.75 / Chapter A --- Proof of Equation (4.9) --- p.77 / Chapter B --- Proof of Equation (4.11) --- p.79 / Bibliography --- p.81

Leung, Yiu-Wing. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 150-157). / Acknowledgments / Abstract / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Broadband Video Services --- p.1 / Chapter 1.3 --- Videoconference Services --- p.7 / Chapter 1.4 --- Videoconference Systems --- p.8 / Chapter 1.5 --- Chapter Summary and Thesis Organization --- p.18 / Chapter Chapter 2 --- Efficient Algorithms for Multiple Destinations Routing --- p.20 / Chapter 2.1 --- Background --- p.20 / Chapter 2.2 --- Integer Programming Formulation of the MDR Problem --- p.26 / Chapter 2.3 --- Heuristics for Multiple Destinations Routing --- p.27 / Chapter 2.4 --- Performance Comparisons --- p.40 / Chapter 2.5 --- Chapter Summary --- p.50 / Chapter Chapter 3 --- Connection Optimization for Two Types of Videoconferences --- p.51 / Chapter 3.1 --- Background --- p.51 / Chapter 3.2 --- The Videoconference Services --- p.52 / Chapter 3.3 --- Connection Optimization --- p.54 / Chapter 3.4 --- Performance Analysis --- p.62 / Chapter 3.5 --- Chapter Summary --- p.80 / Chapter Chapter 4 --- A TDM-based Multibus Packet Switch --- p.81 / Chapter 4.1 --- Background --- p.81 / Chapter 4.2 --- Architecture of the Multibus Switch --- p.89 / Chapter 4.3 --- Operation of the Multibus Switch --- p.93 / Chapter 4.4 --- Performance Analysis --- p.95 / Chapter 4.5 --- Numerical Results --- p.106 / Chapter 4.6 --- Discussions --- p.109 / Chapter 4.7 --- Chapter Summary --- p.113 / Chapter Chapter 5 --- A Modular Shared Media Video Switch --- p.114 / Chapter 5.1 --- System Architecture and Operation --- p.114 / Chapter 5.2 --- Slot Assignment for Point-to-Point Transmissions --- p.129 / Chapter 5.3 --- Slot Assignment for Point-to-Multipoint Transmissions --- p.132 / Chapter 5.4 --- Network Design Example --- p.136 / Chapter 5.5 --- Chapter Summary --- p.143 / Appendix --- p.144 / Chapter Chapter 6 --- Conclusions --- p.147 / References --- p.150

Lee Chun Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leave 45). / List of Figures --- p.iii / List of Tables --- p.iv / Acknowledgement --- p.v / Abstract --- p.vi / Chapter I --- Introduction --- p.1 / Chapter II --- Architecture of The Proposed Lightwave Backbone Network --- p.4 / Chapter III --- Wavelength Conflicts Problem --- p.8 / Chapter IV --- Network Dimensioning Problem --- p.10 / Chapter A. --- Integer Programming Formulation --- p.10 / Chapter V --- Capacity Apportionment (CA) Problem --- p.17 / Chapter A. --- Integer Programming Formulation --- p.17 / Chapter B. --- Heuristic Algorithm --- p.19 / Chapter C. --- An Illustrative Example For The Hueristic Algorithm --- p.21 / Chapter VI --- Wavelength Channel Assignment Problem --- p.24 / Chapter A. --- Wavelength Channel Assignment Strategies --- p.24 / Chapter B. --- Dynamic Wavelength Channel Assignment Algorithms --- p.25 / Chapter C. --- Performance Results By simulation --- p.33 / Chapter D. --- Comparison Of Blocking Performance Between Static And Dynamic Wavelength Channel Assignment Scheme --- p.40 / Chapter VII --- Conclusion --- p.42 / References --- p.45 / Appendix A Wavelength channel assignment plan generated by the heuristic algorithm for the illustrative example in section V --- p.46

Chan Ming-fei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 63-66). / Abstract --- p.i / Acknowledgments --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Challenging Issues --- p.2 / Chapter 1.2 --- Previous Work --- p.4 / Chapter 1.3 --- Organization of the Thesis --- p.5 / Chapter 2 --- Distributed Virtual Environment --- p.6 / Chapter 2.1 --- Possible Architectures --- p.6 / Chapter 2.2 --- Representations of Clients as Avatars --- p.7 / Chapter 2.3 --- Dynamic Membership --- p.9 / Chapter 3 --- Bandwidth and Computation Reduction Techniques --- p.11 / Chapter 3.1 --- Network Communication --- p.12 / Chapter 3.2 --- Dead Reckoning --- p.13 / Chapter 3.3 --- Message Aggregation --- p.15 / Chapter 3.3.1 --- Network-Based Aggregation --- p.15 / Chapter 3.3.2 --- Organization-Based Aggregations --- p.16 / Chapter 3.3.3 --- Grid-Based Aggregations --- p.16 / Chapter 3.4 --- Relevance Filtering --- p.17 / Chapter 3.4.1 --- Entity-Based Filtering --- p.17 / Chapter 3.4.2 --- Grid-Based Filtering --- p.19 / Chapter 3.5 --- Quiescent Entities --- p.20 / Chapter 3.6 --- Spatial Partitioning --- p.21 / Chapter 3.6.1 --- Necessity of Spatial Partitioning --- p.22 / Chapter 3.6.2 --- Binary Space Partitioning Tree --- p.23 / Chapter 3.6.3 --- BSP Tree Construction --- p.23 / Chapter 4 --- Partitioning Algorithm --- p.25 / Chapter 4.1 --- Problem Formulation --- p.25 / Chapter 4.2 --- Exhaustive Partition (EP) Algorithm --- p.28 / Chapter 4.3 --- Partitioning Algorithm --- p.29 / Chapter 4.3.1 --- Recursive Bisection Partition (RBP) Algorithm --- p.30 / Chapter 4.3.2 --- Layering Partitioning (LP) Algorithm --- p.32 / Chapter 4.3.3 --- Communication Refinement Partitioning (CRP) Algorithm --- p.38 / Chapter 4.4 --- Parallel Approach --- p.42 / Chapter 4.5 --- Further Observation --- p.43 / Chapter 5 --- Experiments --- p.44 / Chapter 5.1 --- Experiment 1: Small Virtual World --- p.45 / Chapter 5.2 --- Experiment 2: Large Virtual World --- p.46 / Chapter 5.3 --- Experiment 3: Moving of Avatars --- p.47 / Chapter 5.4 --- Experiment 4: Dynamic Joining and Leaving --- p.48 / Chapter 5.5 --- Experiment 5: Parallel Approach --- p.49 / Chapter 6 --- Implementation Considerations --- p.55 / Chapter 6.1 --- Different Environments --- p.55 / Chapter 6.2 --- Platform --- p.56 / Chapter 6.3 --- Lessons learned --- p.57 / Chapter 7 --- Conclusion --- p.59 / A Simplex Method --- p.60 / Bibliography --- p.63

Lee Chung Hing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 61-63). / Abstracts in English and Chinese. / Acknowledgements --- p.ii / Abstract --- p.iii / List of Figures --- p.vii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Contributions of This Thesis --- p.3 / Chapter 1.2 --- Organizations of This Thesis --- p.3 / Chapter 1.3 --- Publication --- p.4 / Chapter 2. --- Overview of VoD Systems --- p.5 / Chapter 2.1 --- True VoD --- p.6 / Chapter 2.2 --- Near VoD --- p.7 / Chapter 2.3 --- Related Works --- p.9 / Chapter 2.3.1 --- Batching --- p.9 / Chapter 2.3.2 --- Patching --- p.11 / Chapter 2.3.3 --- Mcache --- p.11 / Chapter 2.3.4 --- Unified VoD --- p.12 / Chapter 2.4 --- Discussions --- p.15 / Chapter 3. --- Super-Scalar Architecture --- p.17 / Chapter 3.1 --- Transmission Scheduling --- p.20 / Chapter 3.2 --- Admission Control --- p.21 / Chapter 3.3 --- Channel Merging --- p.26 / Chapter 3.4 --- Interactive Control --- p.29 / Chapter 4. --- Performance Modeling --- p.31 / Chapter 4.1 --- Waiting Time for Statically-Admitted Clients --- p.32 / Chapter 4.2 --- Waiting Time for Dynamically-Admitted Clients --- p.33 / Chapter 4.3 --- Admission Threshold --- p.38 / Chapter 4.4 --- Channel Partitioning --- p.39 / Chapter 5. --- Performance Evaluation --- p.40 / Chapter 5.1 --- Model Validation --- p.40 / Chapter 5.2 --- Channel Partitioning --- p.42 / Chapter 5.3 --- Latency Comparisons --- p.44 / Chapter 5.4 --- Channel Requirement --- p.46 / Chapter 5.5 --- Performance at Light Loads --- p.47 / Chapter 5.6 --- Multiplexing Gain --- p.49 / Chapter 6. --- Implementation and Benchmarking --- p.51 / Chapter 6.1 --- Implementation Description --- p.51 / Chapter 6.2 --- Benchmarking --- p.53 / Chapter 6.2.1 --- Benchmarking Setup --- p.53 / Chapter 6.2.2 --- Benchmarking Result --- p.55 / Chapter 7. --- Conclusion --- p.56 / Appendix --- p.57 / Bibliography --- p.61

Tung, Tak Fu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 66-68). / Abstracts in English and Chinese. / Chapter 1 --- Introduction to Multi-path Streaming and Dynamic End-point Adaptation --- p.1 / Chapter 1.1 --- Multi-path Streaming --- p.2 / Chapter 1.2 --- Dynamic End-point Adaptation --- p.4 / Chapter 2 --- Related Work --- p.6 / Chapter 3 --- Path Loss Model --- p.10 / Chapter 3.1 --- Bursty Loss --- p.10 / Chapter 3.2 --- Gilbert Model --- p.11 / Chapter 3.2.1 --- Discrete-time Gilbert Model --- p.11 / Chapter 3.2.2 --- Continuous-time Gilbert Model --- p.12 / Chapter 4 --- Loss Recovery / Chapter 4.1 --- Automatic Repeat Request (ARQ) --- p.17 / Chapter 4.2 --- Forward Error Correction (FEC) --- p.18 / Chapter 5 --- Connection Adaptation --- p.23 / Chapter 5.1 --- Path Quality --- p.23 / Chapter 5.2 --- Effect of Shared Congestion Point --- p.24 / Chapter 5.2.1 --- Point-of-Congestion Detection --- p.25 / Chapter 5.3 --- Load Distribution --- p.27 / Chapter 6 --- Analytical Evaluation --- p.28 / Chapter 6.1 --- Performance Analysis of SP vs. Multi-path Streaming (without FEC) --- p.29 / Chapter 6.2 --- Performance Analysis of SP vs. Multi-path Streaming (with FEC) --- p.36 / Chapter 7 --- Experiments and Simulations --- p.42 / Chapter 7.1 --- Effect of Correlated Bursty Losses on Video Quality --- p.42 / Chapter 7.2 --- Analytical Model Based Evaluation --- p.44 / Chapter 7.2.1 --- Data Loss Rate --- p.44 / Chapter 7.2.2 --- Data Loss Rate as a function of FEC parameters --- p.46 / Chapter 7.2.3 --- Conditional Error Burst Length --- p.48 / Chapter 7.2.4 --- Lag-1 Autocorrelation --- p.49 / Chapter 7.2.5 --- Effects of Load Distribution Among Senders --- p.50 / Chapter 7.2.6 --- Sensitivity Analysis --- p.51 / Chapter 7.2.7 --- Effects of Shared Points of Congestion on Various Perfor- mance Metrics --- p.53 / Chapter 7.3 --- Simulation Model Based Evaluation --- p.55 / Chapter 7.3.1 --- Simulation Setup --- p.55 / Chapter 7.3.2 --- Data Loss Rate --- p.57 / Chapter 7.3.3 --- Data Loss Rate as a function of FEC parameters --- p.58 / Chapter 7.3.4 --- Conditional Error Burst Length --- p.59 / Chapter 7.3.5 --- Lag-1 Autocorrelation --- p.60 / Chapter 7.3.6 --- Effects of Load Distribution among Senders --- p.61 / Chapter 7.3.7 --- Sensitivity Analysis --- p.62 / Chapter 7.3.8 --- Effects of Shared Points of Congestion on Various Perfor- mance Metrics --- p.63 / Chapter 8 --- Conclusion --- p.65