In 3GPP Release 5 and beyond, an All-IP architecture has been specified. This indicates that convergence of mobile applications such as voice, video and gaming to IP is not a "trend" anymore, but a reality. IP mobility has therefore been intensively studied in recent years. Majority of the existing IP mobility schemes, including Mobile IPv6 (MIPv6), the current de facto standard solution for IP mobility, are designed around a two-tier addressing model. In this model, while visiting a foreign link, a mobile node (MN) is identified by its home address assigned by its home link but is located by the care-of-address (CoA) acquired from the foreign link. Incoming packets for the MN are routed to its home link as usual, but are intercepted by the home agent and tunneled to the CoA. This model is simple and is well accepted. However, when it comes to real-time applications, it also has been known to be ineffective in terms of handoff delay and bandwidth consumption due to, respectively, its lengthy CoA acquisition and the extra IP header for tunneling. The latter is especially expensive for the case of real-time applications because of the excessive overhead induced by the extra IP header (20 bytes for IPv4 and 40 bytes for IPv6) to the packet payload size (∼20-160 bytes). / In this thesis, we show that (i) can be overcome when a direct Layer-3 connection between the home and any particular visiting domain is available so that inter-domain routing effectively becomes routing within the same logical hierarchy. We call a global network formed by the directly Layer-3 connected domains the Global Universal Addressing (GUA) framework. When deployed on the GUA framework, the existing local mobility schemes can easily be upgraded to support global mobility as seamlessly as local mobility with no modification needed. / Much work has been devoted to improving the two-tier addressing model, including various local mobility schemes such as HAWAII and Cellular IP. These schemes eliminate the CoA acquisition when the MNs move within one domain, but revert back to the two-tier addressing model when the mobility is across different domains (or so-called global mobility). These schemes therefore inherit all the drawbacks of the two-tier addressing model when it comes to global mobility. It has been argued that mobility across domains is rare. However, looking into the near future, this assumption is certainly not applicable to the upcoming fourth-generation (4G) wireless architecture in which the MNs can dynamically choose the best connected wireless interface among heterogeneous networks (e.g., WiFi, WiMax, etc.) of different domains as they move. Therefore, an efficient solution is needed to handle the frequent inter-domain mobility, or global mobility, in the form of heterogeneous handoffs as well. / To address (ii), we propose a new IP mobility scheme called Cellular Universal IP (CUIP), which runs on the GUA framework and makes use of a home route concept also proposed in this thesis. The home route concept intelligently integrates the efficiency of prefix routing and flexibility of full-address routing to achieve high performance and routing scalability under the universal addressing model. In addition, based on IPv6, CUIP makes use of the IPv6 option header to embed the route-update information of an MN in the outgoing data packets for a short period after handoff, so that global routing information can be effectively updated along the path traversed by the packets. We study the performance of CUIP quantitatively and show the following: (1) the average number of routers updated per handoff is less than three, so that the average handoff delay is minimal. (2) The routing table complexity is asymptotically independent of the depth and monotonically decreasing with the width of the network hierarchy. That is, routing scalability is not a concern even in large networks. / To efficiently support global mobility, a universal addressing model, under which a mobile node is always identified and located by the same IP address globally, is an obvious answer to the problems associated with the two-tier addressing model. However, the universal addressing model has been considered to be infeasible due to difficulties in (i) inter-domain (or cross-prefix) IP routing and (ii) routing table scaling. / by Lam, Pak Kit. / "June 2007." / Adviser: Soung Liew. / Source: Dissertation Abstracts International, Volume: 69-01, Section: B, page: 0553. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 128-130). / 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.

Xu, Yang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 99-104). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background of Sensors and Sensor Networks --- p.2 / Chapter 1.2 --- Introduction to Coverage Problems --- p.6 / Chapter 1.3 --- Literature Review --- p.8 / Chapter 1.3.1 --- Deterministic Deployment Methods --- p.9 / Chapter 1.3.2 --- Dynamic Deployment Methods --- p.10 / Chapter 1.4 --- A Brief Introduction to Least Squares Analysis --- p.13 / Chapter 1.5 --- Thesis Outline --- p.15 / Chapter 2 --- Mobile Sensor Network Deployment Problem --- p.18 / Chapter 2.1 --- Sensor Coverage Models --- p.18 / Chapter 2.1.1 --- Binary Sensor Models --- p.19 / Chapter 2.1.2 --- Attenuated and Truncated Attenuated Disk Models --- p.20 / Chapter 2.2 --- Problem Statement --- p.23 / Chapter 3 --- Coverage Optimization as Nonlinear Least Squares Problems --- p.26 / Chapter 3.1 --- Introduction --- p.26 / Chapter 3.2 --- Network Deployment as Least Squares Problems --- p.28 / Chapter 3.2.1 --- Assignment of Sample Points --- p.28 / Chapter 3.2.2 --- Least Squares Function --- p.30 / Chapter 3.2.3 --- Gauss-Newton Method --- p.33 / Chapter 3.2.4 --- Solutions --- p.36 / Chapter 3.3 --- Extension to Binary Sensor Models --- p.39 / Chapter 3.3.1 --- Restrictions of Subgradient Methods --- p.40 / Chapter 3.3.2 --- Sigmoid Functions --- p.42 / Chapter 3.4 --- Convergence and Multiple Minima Issues --- p.44 / Chapter 3.4.1 --- Convergence --- p.44 / Chapter 3.4.2 --- Multiple Minima --- p.48 / Chapter 3.5 --- Stopping Criteria --- p.52 / Chapter 3.6 --- Summary --- p.53 / Chapter 4 --- Experimental Results --- p.55 / Chapter 4.1 --- Introduction --- p.55 / Chapter 4.2 --- Numerical Examples --- p.56 / Chapter 4.2.1 --- Examples of Attenuated Disk Models --- p.57 / Chapter 4.2.2 --- Examples of Binary Sensor Models --- p.63 / Chapter 4.3 --- Performance Metrics of Mobile Sensor Deployment Schemes --- p.68 / Chapter 4.4 --- Comparison to Existing Methods --- p.74 / Chapter 4.5 --- Summary --- p.81 / Chapter 5 --- Conclusions --- p.83 / Chapter 5.1 --- Conclusions --- p.83 / Chapter 5.2 --- Future Research Directions --- p.85 / Appendices --- p.87 / Chapter A --- An Overview of Existing Deployment Methods --- p.88 / Chapter A.1 --- Potential Fields and Virtual Forces --- p.88 / Chapter A.2 --- Distributed Self-Spreading Algorithm --- p.92 / Chapter A.3 --- VD-Based Deployment Algorithm --- p.96 / Bibliography --- p.99

Law, Carlos. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 119-122). / Abstracts in English and Chinese. / Abstract --- p.i / 論文摘要 --- p.iii / Acknowledgement --- p.v / Table of Content --- p.vi / List of Figures --- p.ix / List of Tables --- p.xv / List of Abbreviations --- p.xvi / Chapter Chapter 1: --- Introduction --- p.1 / Chapter 1.1 --- Emergence of Multi-band Microwave Circuits --- p.1 / Chapter 1.2 --- Original Contribution --- p.2 / Chapter 1.3 --- Overview of the Thesis Organization --- p.3 / Chapter 1.4 --- "Research Approach, Assumptions and Limitations" --- p.5 / Chapter Chapter 2： --- Fundamentals in Filter and Power Divider Design --- p.7 / Chapter 2.1 --- Filter --- p.7 / Chapter 2.1.1 --- Introduction to Filters --- p.7 / Chapter 2.1.2 --- Transfer Function --- p.8 / Chapter 2.1.3 --- Low-pass Prototype and Elements --- p.11 / Chapter 2.1.4 --- Admittance Inverters --- p.13 / Chapter 2.2 --- Power Divider --- p.20 / Chapter 2.2.1 --- Introduction to Power Dividers --- p.20 / Chapter 2.2.2 --- Wilkinson Power Divider --- p.21 / Chapter 2.2.3 --- Multi-section Power Divider --- p.25 / Chapter 2.2.4 --- Power Divider with Unequal Power Division --- p.27 / Chapter Chapter 3： --- Conventional Multi-band Designs --- p.29 / Chapter 3.1 --- Micro-strip Multi-band Filters --- p.29 / Chapter 3.1.1 --- Parallel Connection of Two Single-band Filters --- p.29 / Chapter 3.1.2 --- "Wide-band, Band-pass Filter and a Band-stop Filter in Cascade" --- p.32 / Chapter 3.1.3 --- Parallel-coupled SIR-based Dual-band Filter --- p.33 / Chapter 3.1.4 --- Vertical-stacked SIR-based Dual-band Filter --- p.34 / Chapter 3.1.5 --- Cross-coupled Hairpin SIR Dual-band Filter --- p.37 / Chapter 3.1.6 --- Folded Open-loop Ring Resonator-based Multi-band Filters --- p.38 / Chapter 3.1.7 --- Stubbed SIR-based Single-band Filter --- p.40 / Chapter 3.1.8 --- Open and Short-circuited Stub-based Dual-band Filter --- p.41 / Chapter 3.1.9 --- Open Stub-based Dual-band Filter --- p.42 / Chapter 3.2 --- Spurious Suppression Techniques for Filters --- p.43 / Chapter 3.2.1 --- Insertion of Band-reject Filters --- p.43 / Chapter 3.2.2 --- Equalization of Eigen-mode Phase Velocities --- p.43 / Chapter 3.2.3 --- Insertion of Open Stubs --- p.45 / Chapter 3.2.4 --- Coupled SIR-based Structures --- p.47 / Chapter 3.2.5 --- Parallel Coupled Line --- p.49 / Chapter 3.2.6 --- Others --- p.50 / Chapter 3.3 --- Dual-band Power Dividers --- p.51 / Chapter 3.3.1 --- Two-section Transmission Line Topology --- p.51 / Chapter 3.3.2 --- Lumped Element-based Topology --- p.53 / Chapter 3.3.3 --- Shunt Stub Topology --- p.56 / Chapter Chapter 4: --- New Dual-band Filter with Wide Upper Stop-band … --- p.59 / Chapter 4.1 --- Proposed Topology --- p.60 / Chapter 4.2 --- Design and Analysis --- p.61 / Chapter 4.3 --- Design Example --- p.73 / Chapter 4.4 --- Summary --- p.79 / Chapter Chapter 5: --- New Tri-band Filter Design --- p.80 / Chapter 5.1 --- Proposed Topology --- p.80 / Chapter 5.2 --- Design and Analysis --- p.82 / Chapter 5.3 --- Design Example --- p.86 / Chapter 5.4 --- Summary --- p.91 / Chapter Chapter 6: --- New Dual-band Power Divider Design I --- p.92 / Chapter 6.1 --- Proposed Topology --- p.92 / Chapter 6.2 --- Design and Analysis --- p.94 / Chapter 6.3 --- Design Example --- p.98 / Chapter 6.4 --- Summary --- p.107 / Chapter Chapter 7: --- New Dual-band Power Divider Design II --- p.108 / Chapter 7.1 --- Proposed Topology --- p.108 / Chapter 7.2 --- Design and Analysis --- p.109 / Chapter 7.3 --- Design Example --- p.112 / Chapter 7.4 --- Summary --- p.115 / Chapter Chapter 8: --- Conclusion --- p.116 / Recommendation for Future Work --- p.118 / References --- p.119 / Author's Publications --- p.123 / Appendix 1: ABCD Parameters --- p.124 / Appendix 2: Program for Tri-band Filter --- p.125 / Appendix 3: Comparison of Dual-band Power Dividers --- p.129 / Appendix 4: Sensitivity of Power Divider to Resistor Variation --- p.146

Zero-Correlation-Zone (ZCZ) codes differ from traditional spreading codes because they contain a region in their correlation functions where the correlation values are null. In these regions the spreading codes are considered ideal, and because of the ZCZ the inter-symbol interference (ISI) and multiple-access interference (MAI) are reduced leading to an increase in capacity and bitrate. This thesis will present a study of ZCZ codes and then will propose a new CDMA system that employs the use of ZCZ codes in particular Loosely Synchronous (LS) codes. This new system shall have its performance compared with an equivalent existing CDMA system (IS-95) and the results shall be shown and discussed. In this comparative study the thesis will also present and examine a tracking performance comparison between ZCZ codes and a traditional spreading code such as m-sequences. It is shown that the performance of the new CDMA system employing ZCZ codes outperforms the traditional CDMA system in a multi-user multipath environment. It is also found that based on the study performed there appears to be no advantage in tracking between a ZCZ code and m-sequences however a more comprehensive study in a multi-user environment is still needed before a conclusion on tracking can be made. / Master of Engineering (Hons.)

This study is aimed at solving several important problems relating to power control in CDMA systems. Our focus is on the mobile to basestation (reverse) link. In this study, we propose a new SIR estimator for CDMA systems, using an auxiliary spreading sequence method. The proposed SIR estimator is employed at the basestation to estimate the SIR, which serves as a control parameter in the power control algorithm. The effects of system parameters (step size, power-update rate, feedback delay, SIR measurement error, and command error) on the bit error rate (BER) performance of power control are investigated. Feedback delay is found to be the most critical parameter that causes a serious problem in the loop. To solve this problem, we propose to use a channel prediction technique at the basestation. To further improve the performance of power control, we then propose to use a diversity reception technique using antenna arrays at the basestation. We show that this combination allows solving the problems linked to the use of power control in a real system affected by multiple access interference under fading conditions. / thesis (PhD)--University of South Australia, 2003.

The Global System for Mobile communications (GSM), which covers 54% of the world's mobile market, evolved into the General Packet Radio Service (GPRS). The thesis addresses interference suppression using new radio frequency (RF) and microwave design methods for GSM and GPRS. The overall outcome is interference reduction and enhanced network capacity, leading to superior quality of service (QoS) for wider area coverage. The main results can be summarized as follows * Design, manufacturing and characterisation measurements of new compact filters for GSM and GPRS base stations in order to reduce the out-of-band interference. It is shown that filters with novel microstrip resonators - dual mode filters and cross coupled filters - provide both a high degree of miniaturisation and narrow bandwidth. * Development of a new 3-D Finite-Difference Time-Domain (FDTD) design method for new microstrip filters. A non-homogeneous Perfectly Matched Layer (NH-PML) was implemented for Absorbing Boundary Conditions (ABC) to increase the accuracy of the FDTD method. Signal estimation techniques were developed to speed up FDTD computations. A novel design method based on neural networks (NN) and FDTD was implemented to reduce the total design time. * Investigation of High Temperature Superconductors (HTS) thin film resonators and antennas at microwave frequencies. High Q-factor HTS devices considerably enhance both the front-ends sensitivity and selectivity of wireless receivers. * Design, manufacturing and testing of radio frequency (RF) electronics for 16 elements GSM and GPRS Smart Antenna for multipath fading mitigation and for in-band interference including co-channel interference (CCI) suppression.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

The widespread use of TCP as a transport layer protocol for mobile ad-hoc networks and wireline networks has motivated the need to make its implementation highly power efficient specially with respect to ad hoc radio networks. Over the past years many researchers have developed energy efficient protocols for mobile ad-hoc networks. This thesis deals with the various modifications and fine-tunings in the TCP code which, when applied, help in conserving battery power at nodes by saving on the software overhead at the mobile nodes. The various modifications proposed have been tested with actual experiments done on two laptops with Lucent WaveLan wireless cards. The results obtained from the experiments indicate that with certain modifications made in the implementation of TCP code, significant savings in power can be achieved along with an increase in the overall efficiency of TCP over wireless links. Finally, a discussion of how other modifications can be researched and tested as the hardware for mobile systems change is proposed. / Graduation date: 2000

Thesis (M.E.)--University of Florida, 2001. / Title from title page of source document. Document formatted into pages; contains xi, 76 p.; also contains graphics. Includes vita. Includes bibliographical references.

Originally presented as the author's thesis (Swiss Federal Institute of Technology), Diss. ETH No. 16687. / Summary in German and English, text in English. Includes bibliographical references (p. 175-180).