Gao Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 70-73). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Literature Survey and Background --- p.6 / Chapter 2.1 --- Capacity of Wireless Networks --- p.6 / Chapter 2.2 --- Physical Layer Techniques --- p.8 / Chapter 2.2.1 --- Radio Propagation Models --- p.8 / Chapter 2.2.2 --- Multiple Access Techniques --- p.11 / Chapter 2.3 --- MAC layer --- p.13 / Chapter 2.3.1 --- An Introduction to the IEEE 802.11 protocol --- p.13 / Chapter 2.3.2 --- Performance Analysis of the IEEE 802.11 protocol in single cell networks --- p.15 / Chapter 3 --- Model and Methodology --- p.18 / Chapter 3.1 --- System Model --- p.18 / Chapter 3.1.1 --- DCF Model --- p.19 / Chapter 3.1.2 --- The Problems of Hidden Node --- p.21 / Chapter 3.2 --- A Methodology to Compute Throughput Capacity --- p.23 / Chapter 3.2.1 --- Constructing a Contention Graph --- p.24 / Chapter 3.2.2 --- Determining the Link Capacity Ei --- p.27 / Chapter 3.2.3 --- Determining the Channel Idle Probability zi --- p.30 / Chapter 3.2.4 --- Detennining the Collision Probability γi --- p.32 / Chapter 3.3 --- Throughput Analysis of a Chain network --- p.35 / Chapter 4 --- Applications of the Proposed Methodology --- p.38 / Chapter 4.1 --- Application 1: Determining the End-to-End Throughput Capacity in Multi-hop Networks --- p.38 / Chapter 4.1.1 --- Routing Optimization --- p.40 / Chapter 4.1.2 --- Offered Load Control --- p.45 / Chapter 4.2 --- Application 2: Determining the Equilibrium Throughput of onehop Networks --- p.47 / Chapter 4.2.1 --- Throughput Capacity of One-Hop Networks --- p.49 / Chapter 4.3 --- Application 3: Optimal Hop Distance in Multi-hop Networks --- p.51 / Chapter 4.3.1 --- Analysis of Regular One-Dimension Network --- p.51 / Chapter 4.3.2 --- Optimal Hop Distance --- p.53 / Chapter 5 --- Simulation and Validation --- p.55 / Chapter 5.1 --- Simulation Environment --- p.55 / Chapter 5.2 --- MAC layer Collisions --- p.56 / Chapter 5.3 --- Single Flow Capacity: --- p.58 / Chapter 5.4 --- Neighboring Traffic Effect: --- p.59 / Chapter 5.5 --- Routing Optimization: --- p.60 / Chapter 5.6 --- Optimal Offered Load Control: --- p.62 / Chapter 5.7 --- Optimal Hop Distance --- p.63 / Chapter 5.7.1 --- One-Source ROD Network --- p.63 / Chapter 5.7.2 --- Two-Source ROD Network --- p.64 / Chapter 5.7.3 --- Simulation Investigation on Hop Distance --- p.65 / Chapter 6 --- Related Work --- p.68 / Chapter 7 --- Conclusion --- p.69

Cheung Cheuk Lun. / Thesis submitted in: July 2004. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 109). / Abstracts in English and Chinese. / Abstract --- p.1 / Chapter 1 --- Introduction --- p.3 / Chapter 1.1 --- Differentiation from existing products --- p.6 / Chapter 1.2 --- Problems --- p.6 / Chapter 1.3 --- Assumption --- p.9 / Chapter 2 --- Study of bulk transfer --- p.10 / Chapter 2.1 --- Simple wireless solution --- p.10 / Chapter 2.2 --- Problems of the simple wireless solution --- p.10 / Chapter 2.2.1 --- Low performance due to header overhead --- p.12 / Chapter 2.2.2 --- Low performance due to unnecessary packets --- p.12 / Chapter 2.2.3 --- Model derivation --- p.12 / Chapter 2.2.4 --- Performance study --- p.17 / Chapter 2.3 --- Packed wireless solution --- p.19 / Chapter 2.3.1 --- Example --- p.19 / Chapter 2.3.2 --- Solved problems --- p.21 / Chapter 2.3.3 --- Model derivation --- p.22 / Chapter 2.3.4 --- Performance study --- p.24 / Chapter 2.3.4 --- Performance study on the effect of the value of n --- p.25 / Chapter 2.4 --- Controllable packed wireless solution --- p.27 / Chapter 2.4.1 --- Problem --- p.27 / Chapter 2.4.2 --- Analysis --- p.27 / Chapter 2.4.3 --- Solution --- p.29 / Chapter 2.4.4 --- Model derivation --- p.33 / Chapter 2.4.5 --- Performance study --- p.35 / Chapter 2.4.6 --- Performance study on the effect of the sliding window size --- p.36 / Chapter 2.5 --- Summary of performance study --- p.41 / Chapter 2.5.1 --- Comparison of the throughput between four cases --- p.41 / Chapter 2.5.2 --- Study of how the throughput-varies with the processing time --- p.44 / Chapter 2.6 --- Simulation --- p.47 / Chapter 2.6.1 --- Measuring the packet loss rate and the throughput --- p.49 / Chapter 2.6.2 --- Studying the throughput against the distance --- p.50 / Chapter 2.6.3 --- Studying the throughput against the packet loss rate --- p.53 / Chapter 2.7 --- Conclusion --- p.54 / Chapter 3 --- Study of interrupt transfer --- p.55 / Chapter 3.1 --- Problem --- p.55 / Chapter 3.2 --- Solution --- p.56 / Chapter 3.2.1 --- Remote polling --- p.56 / Chapter 3.3 --- Feasibility of the solution --- p.58 / Chapter 3.4 --- The problem of Distributed Coordination Function collision --- p.60 / Chapter 3.5 --- Collision avoidance --- p.60 / Chapter 3.6 --- Model derivation --- p.61 / Chapter 3.6.1 --- Wired case --- p.61 / Chapter 3.6.2 --- Wireless solution (remote polling) --- p.62 / Chapter 3.7 --- Maximum allowed request generation frequency --- p.64 / Chapter 3.7.1 --- More than one interrupt transfer --- p.64 / Chapter 3.7.2 --- More than one bulk transfer --- p.64 / Chapter 3.7.3 --- Maximum allowed request generation frequency --- p.65 / Chapter 3.8 --- Conclusion --- p.65 / Chapter 4 --- System architecture issues --- p.66 / Chapter 4.1 --- USB network --- p.66 / Chapter 4.1.1 --- Problems --- p.66 / Chapter 4.1.2 --- Solution --- p.66 / Chapter 4.1.3 --- Conclusion --- p.69 / Chapter 4.2 --- Security --- p.70 / Chapter 4.2.1 --- Suggested solution --- p.70 / Chapter 4.2.2 --- Conclusion --- p.72 / Chapter 4.3 --- Cost --- p.72 / Chapter 4.4 --- Power supply --- p.73 / Chapter 5 --- Conclusion --- p.75 / Appendix --- p.77 / Chapter A. --- Wireless USB (WUSB) --- p.77 / Chapter B. --- Introduction of USB --- p.83 / Chapter C. --- Framing details of 802.11 --- p.99 / Chapter D. --- A case study of a USB device --- p.102 / Chapter E. --- Reference of notations used in figures --- p.106 / Chapter F. --- Values of all symbols --- p.107 / Reference i --- p.109

Jiang Libin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 84-87). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivations and Contributions --- p.1 / Chapter 1.2 --- Related Works --- p.3 / Chapter 1.3 --- Organization of the Thesis --- p.4 / Chapter Chapter 2 --- Background --- p.6 / Chapter 2.1 --- IEEE 802.11 --- p.6 / Chapter 2.1.1 --- Basics of 802.11 Standard --- p.6 / Chapter 2.1.2 --- Types of Networks --- p.10 / Chapter 2.1.3 --- Automatic Repeat request (ARQ) in 802.11b --- p.11 / Chapter 2.2 --- Hidden- and Exposed-node Problems --- p.15 / Chapter Chapter 3 --- Physical Interference Constraints and Protocol Constraints --- p.19 / Chapter 3.1 --- Protocol-independent Physical Interference Constraints --- p.19 / Chapter 3.2 --- Protocol-specific Physical Interference Constraints --- p.21 / Chapter 3.3 --- Protocol Collision-Prevention Constraints in 802.11 --- p.22 / Chapter 3.3.1 --- Transmitter-Side Carrier-Sensing Constraints --- p.22 / Chapter 3.3.2 --- Receiver-Side Carrier Sensing Constraints --- p.24 / Chapter Chapter 4 --- Formal Definitions of EN and HN Using a Graph Model --- p.27 / Chapter Chapter 5 --- Selective Disregard of NAVs (SDN) --- p.36 / Chapter 5.1 --- SDN. I - Turning off Physical Carrier Sensing and Using Receiver Restart Mode --- p.38 / Chapter 5.2 --- SDN.II - Selective Disregard of NAV (SDN) --- p.38 / Chapter 5.3 --- SDN.III - Constructing s-graph using Power Exchange Algorithm (PE) --- p.40 / Chapter Chapter 6 --- EN and Its Impact on Scalability --- p.42 / Chapter 6.1 --- Validation of SDN by NS-2 Simulations --- p.43 / Chapter 6.2 --- Scalability of SDN --- p.46 / Chapter 6.3 --- Non-Scalability of 802.11 --- p.47 / Chapter Chapter 7 --- Hidden-node Free Design (HFD) --- p.51 / Chapter 7.1 --- HFD for IEEE 802.11 Basic Access Mode --- p.52 / Chapter 7.1.1 --- HFD for basic access mode --- p.52 / Chapter 7.1.2 --- Proof of the HN-free property --- p.56 / Chapter 7.2 --- HFD for IEEE 802.11 RTS/CTS Access Mode --- p.59 / Chapter Chapter 8 --- Performance Evaluation of HFD --- p.62 / Chapter 8.1 --- HFD for Basic Access Mode --- p.62 / Chapter 8.2 --- HFD for RTS/CTS Access Mode --- p.64 / Chapter Chapter 9 --- Combination of SDN and HFD --- p.68 / Chapter Chapter 10 --- Conclusion --- p.75 / Appendices --- p.78 / References --- p.84

Ng Ping-chung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 71-72). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview and Motivation --- p.1 / Chapter 1.2 --- Background of Offered Load Control --- p.2 / Chapter 1.3 --- Background of Stability Control --- p.3 / Chapter 1.4 --- Organization of the Thesis --- p.4 / Chapter Chapter 2 --- Performance Problems and Solutions --- p.6 / Chapter 2.1 --- Simulation Set-up --- p.6 / Chapter 2.2 --- High Packet-Drop Rate --- p.7 / Chapter 2.3 --- Re-routing Instability --- p.8 / Chapter 2.3.1 --- Hidden-Node Problem --- p.8 / Chapter 2.3.2 --- Ineffectiveness of Solving Hidden-Node Problem with RTS/CTS …… --- p.9 / Chapter 2.4 --- Solutions to High-Packet Loss Rate and Re-routing Instability --- p.10 / Chapter 2.4.1 --- Link-Failure Re-routing --- p.11 / Chapter 2.4.2 --- Controlling Offered Load --- p.13 / Chapter 2.5 --- Verification of Simulation Results with Real-life Experimental Measurements --- p.14 / Chapter Chapter 3 --- Offered Load Control --- p.16 / Chapter 3.1 --- Capacity Limited by the Hidden-node and Exposed-node Problems --- p.16 / Chapter 3.1.1 --- Signal Capture --- p.18 / Chapter 3.1.2 --- Analysis of Vulnerable Period induced by Hidden Nodes --- p.20 / Chapter 3.1.3 --- Analysis of Vulnerable Period induced by Exposed Nodes --- p.21 / Chapter 3.1.4 --- Sustainable Throughput --- p.22 / Chapter 3.2 --- Capacity Limited by Carrier Sensing Property --- p.23 / Chapter 3.3 --- Numerical Results --- p.26 / Chapter 3.4 --- General Throughput Analysis of a Single Multi-hop Traffic Flow --- p.29 / Chapter 3.5 --- Throughput Analysis on Topologies with Variable Distances between Successive Nodes --- p.31 / Chapter Chapter 4 --- Discussions of Other Special Cases --- p.33 / Chapter 4.1 --- A Carrier-sensing Limited Example --- p.33 / Chapter 4.2 --- A Practical Solution to Improve Throughput --- p.34 / Chapter Chapter 5 --- Achieving Fairness in Other Network Topologies --- p.36 / Chapter 5.1 --- Lattice Topology --- p.36 / Chapter Chapter 6 --- Stability Control --- p.39 / Chapter 6.1 --- Ad-hoc routing protocols --- p.39 / Chapter 6.2 --- Proposed scheme --- p.40 / Chapter 6.2.1 --- Original AODV --- p.41 / Chapter 6.2.2 --- AODV with Proposed Scheme --- p.42 / Chapter 6.2.2.1 --- A Single Flow in a Single Chain of Nodes --- p.43 / Chapter 6.2.2.2 --- Real-break Case --- p.44 / Chapter 6.3 --- Improvements --- p.45 / Chapter Chapter 7 --- Impacts of Data Transmission Rate and Payload Size --- p.48 / Chapter 7.1 --- Signal Capture --- p.48 / Chapter 7.2 --- Vulnerable region --- p.50 / Chapter Chapter 8 --- Performance Enhancements in Multiple Flows --- p.53 / Chapter 8.1 --- Impacts of Re-routing Instability in Two Flow Topology --- p.53 / Chapter 8.2 --- Impacts of Vulnerable Periods in Multiple Flow Topologies --- p.55 / Chapter 8.2.1 --- The Vulnerable Period induced by Individual Hidden-terminal Flow --- p.57 / Chapter 8.2.2 --- The Number of Hidden-terminal Flows --- p.58 / Chapter 8.2.3 --- Correlation between Hidden-terminal Flows --- p.60 / Chapter Chapter 9 --- Conclusion --- p.63 / Chapter Appendix A: --- General Throughput Analysis of a Single Multi-hop Traffic Flow --- p.67 / Chapter A.l --- Capacity Limited by Hidden-node and Exposed-Node --- p.67 / Chapter A.1.1 --- Sustainable Throughput --- p.68 / Chapter A.2 --- Capacity Limited by Carrier Sensing Property --- p.68 / Bibliography --- p.71

Nam Chung Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 68-71). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview and Motivation --- p.1 / Chapter 1.2 --- Organization of the Thesis --- p.5 / Chapter Chapter 2 --- Background --- p.6 / Chapter 2.1 --- Basics of 802.11 Standard --- p.6 / Chapter 2.1.1 --- Distributed Coordination Function (DCF) / Point Coordination Function (PCF) --- p.7 / Chapter 2.1.2 --- RTS/CTS --- p.8 / Chapter 2.2 --- Types of Networks --- p.9 / Chapter 2.3 --- Automatic Repeat request (ARQ) in 802.11b --- p.11 / Chapter 2.3.1 --- Importance of Link-layer ARQ in Wireless Networks --- p.12 / Chapter 2.3.2 --- MAC Algorithm of 802.11b Standard --- p.13 / Chapter 2.3.3 --- Modified MAC algorithm in 802.11b commercial products --- p.14 / Chapter 2.4 --- Automatic Adjustment of Radio Data Rate in Commercial 802.11b Products --- p.15 / Chapter Chapter 3 --- Head-of-Line Blocking in Access Points --- p.17 / Chapter 3.1 --- Cause of HOL blocking in 802.11b --- p.17 / Chapter 3.1.1 --- Calculation of Worst-Case Service Time for Packet at Head of Queue --- p.19 / Chapter 3.2 --- Simulation Settings --- p.21 / Chapter 3.2.1 --- Propagation Models Available in NS2 --- p.21 / Chapter 3.2.2 --- Variables of Shadowing Model --- p.25 / Chapter 3.3 --- Simulation Results on UDP --- p.26 / Chapter 3.4 --- Experimental Results on UDP --- p.28 / Chapter 3.5 --- Simulation Results on TCP --- p.32 / Chapter 3.6 --- Experimental Results on TCP --- p.34 / Chapter 3.7 --- Possible Solutions of HOL Blocking Problem --- p.35 / Chapter 3.7.1 --- Weakening Link-layer ARQ in 802.11b --- p.36 / Chapter 3.7.2 --- Effectiveness of ARQ in 802.11b --- p.37 / Chapter 3.7.2.1 --- Set-up for Network Experiments --- p.38 / Chapter 3.7.2.2 --- Results and Analysis --- p.39 / Chapter 3.7.3 --- Virtual Queuing --- p.45 / Chapter Chapter 4 --- Study of Uplink Traffic --- p.50 / Chapter 4.1 --- Poor Pulling Down the Rich --- p.51 / Chapter 4.2 --- Signal Capturing Effect --- p.53 / Chapter 4.2.1 --- Mathematical Analysis of Signal Capturing Effect --- p.55 / Chapter Chapter 5 --- Packet Loss Patterns in 802.11b WLAN --- p.61 / Chapter 5.1 --- """Random Loss"" vs ""Bursty Loss""" --- p.61 / Chapter 5.2 --- Experimental Evaluation --- p.62 / Chapter Chapter 6 --- Conclusion --- p.65 / Bibliography --- p.68

Thesis (M.S. in Computer Science)--Naval Postgraduate School, March 2004. / Thesis advisor(s): Geoffrey Xie. Includes bibliographical references (p. 131-132). Also available online.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, March 2003. / Thesis advisor(s): Tri T. Ha, Jan E. Tighe. Includes bibliographical references (p. 105). Also available online.

Almost all mobile devices nowadays are enabled with IEEE 802.11 Wireless Local Area Network (WLAN), which is also known as WiFi. One of the most important considerations when choosing an 802.11 device is its battery life. To allow mobile devices to conserve energy, IEEE 802.11 standard specifies a power save mode (PSM). A station/device in PSM, i.e. PSM-STA, will wake up at a predefined listen interval (LI) to receive frames buffered at the access point (AP) while it is sleeping. In this thesis, we focus on enhancing the basic PSM mechanisms in the standard. In particular, two new power saving schemes, delayed wakeup and dynamic listen interval, are proposed. Unlike many existing schemes, our schemes are fully standard compliant, and legacy devices can support them via a firmware upgrade. In our delayed wakeup (DW) scheme, we assume that all PSM-STAs use the same listen interval of one. That is all PSM-STAs wake up at every beacon frame broadcast, or beacon interval (BI). From the traffic indication map (TIM) in the beacon, a PSMSTA learns if there are any buffered frames at AP. If yes, it will stay awake until all buffered frames are retrieved. This creates a rush hour on the shared channel right after a beacon broadcast. If the channel is congested, having all PSM-STAs staying awake will not improve the system delay performance but consume more power. Aiming at saving battery power while not affecting delay-throughput performance, our DWscheme divides a BI into n sub-BIs. Then based on the amount of buffered frames, AP identifies and instructs “excess” stations to sleep immediately and wake up at a non-congested sub-BI later on. “Instructions” are judiciously encoded inside the modified TIM. We show that our modifications are fully transparent to legacy stations. In order to more accurately identify the amount of excess stations, an analytical model is also constructed to derive the saturated throughput of a WLAN consisting of PSM-STAs. In our dynamic listen interval (DLI) scheme, we aim at minimizing unnecessary wakeups while without sacrificing delay performance. Note that when a PSM-STA wakes up to receive a beacon and found that there are no buffered frames at AP, the PSM-STA experiences an unnecessary wakeup. Accordingly, the associated mode transition energy is wasted. According to the IEEE 802.11 standard, each STA chooses its fixed LI at the time of association. If LI=1, a STA wakes up at every beacon interval (as that in DW scheme). Although packet delay is minimized in this case, the chance of unnecessary wakeups can be high. On the other hand, a larger LI can reduce the chance of unnecessary wakeups but the delay will be increased. Our DLI scheme addresses this problem by dynamically adjusting the LI value according to traffic load. Specifically, each unnecessary wakeup will increase a STA’s LI by one, and a necessary wakeup will immediately reset LI to one. Simulations show that when traffic is bursty, mode transition energy consumption can be reduced without noticeable degradation in delay performance. / published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

Thesis (Ph.D.)--McMaster University, 2005. / Supervisor: Terence D. Todd. Includes bibliographical references (leaves 174-186).

Diss. (sammanfattning) Västerås : Univ., 2007. / Härtill 5 uppsatser.