廖婉君臺灣大學：電機工程學研究所曹正霖Tsao, Cheng-linCheng-linTsao2007-11-262018-07-062007-11-262018-07-062004http://ntur.lib.ntu.edu.tw//handle/246246/53261隨著可攜式設備平台上無線通訊與行動計算技術的持續進步，以及使用者對行動通訊的需求增加，移動無線隨意網路(mobile ad hoc network)架構是目前的熱門研究課題。在移動無線隨意網路上設計並評估通訊協定時，不同移動模型下的移動無線隨意網路所具有的動態網路拓撲結構，對上層的各種路由協定效能有不同的影響，例如：該協定對網路拓撲變化的適應性、網路資源有限時的省電效率。在一個移動模型的各種特質裡，網路連線動態是最為關鍵的網路連結特質。random waypoint模型是移動無線隨意網路研究領域裡，最為廣泛使用的一種移動模型。 本碩士論文針對random waypoint模型下移動無線隨意網路之網路連線動態(link dynamics)進行詳細的分析研究，其中包含單一節點的行為特徵、節點間連線維持時間(link duration)之機率分佈。研究過程中我們發現random waypoint模型所展現的不平均分佈(non-uniformly distributed)特質、節點移動速度或無線傳輸距離對網路連線維持時間的影響、以及random waypoint模型參數調整所造成的連線動態之變化。我們在網路連線動態的分析結果，不僅可讓我們對於移動無線隨意網路的動態網路拓撲結構有更深刻的理解，更可提供移動無線隨意網路的效能評估中，諸如路由協定效能、網路穩定性等，分析研究之基礎。我們並以模擬數據來驗證分析結果的正確性。Advances in wireless technology and mobile computing on portable devices, along with the demand for greater user mobility, have provided a major impetus toward the development of an emerging class of self-organizing, rapidly deployable, and highly mobility adaptable network architectures referred as Mobile Ad hoc NETworks (MANETs). When designing and evaluating routing protocols of MANETs, different mobility models form networks with different characteristics of network topology dynamics, which further influence the performance of MANET routing protocols. The performance influences include the adaptability to network topology dynamics and energy efficiency in a network with limited resources. Among all metrics of a mobility model, link dynamics is the most significant network connectivity graph metric. The most commonly used mobility model in the MANET research community is the random waypoint mobility model. In this thesis, we provide an analytical study of the link dynamics in a MANET in which mobile nodes moves according to random waypoint mobility model. The analysis includes the mobility behaviors of a single node and the distribution of link duration between two nodes. We provide in-depth investigation such as the non-uniformity of random waypoint mobility model, the impact of nodal speed and transmission range on link duration, and how parameters of random waypoint mobility model influence link dynamics. Our analytical study about the link dynamics gives us an insight into the network topology dynamics of MANET, and it provides us the basis of further analysis of MANET such as routing protocol performance and network connectivity. Simulation results verify our analysis of the link dynamics of MANET.List of Figures x List of Tables xiii Chapter 1 Introduction 1 1.1 Mobile Ad Hoc Networks 1 1.2 Mobility Models for Mobile Ad Hoc Networks 6 1.3 Motivation 11 1.4 Related Work 13 1.5 Organization 16 Chapter 2 Analysis of Link Duration 17 2.1 Overview of the Analysis 19 2.1.1 Nomenclature of Random Variables 24 2.1.2 Assumptions 25 2.2 Distribution of the Distance between Two Destinations 26 2.3 The Distribution of Link Duration 32 2.3.1 Anticipated Link Duration when Link is Activated 35 2.3.2 Residual Time to Next Mobility Change when Link is Activated 41 2.3.3 Anticipated Link Duration when Movement is Resumed 47 2.3.4 Residual Time to Next Mobility Change when Movement is Resumed 60 2.3.5 Distribution of Link Duration without Pausing 62 Chapter 3 Simulation Verification 65 3.1 Simulation Environment 65 3.2 Simulation Results 67 3.2.1 Simulation Result of the Distance between Two Destinations 67 3.2.2 Simulation Results of Link Duration without Pausing 68 3.2.2.1. Simulation Results of Anticipated Link Duration when Link is Activated 68 3.2.2.2. Simulation Results of Residual Time to Next Mobility Change when Link is Activated 71 3.2.2.3. Simulation Results of Anticipated Link Duration when Movement is Resumed 73 3.2.2.4. Simulation Results of Residual Time to Next Mobility Change when Movement is Resumed 77 3.2.2.5. Simulation Results of the Distribution of Link Duration 79 3.2.2.6. Link Duration Expectations and Variances under Different Scenarios 82 3.2.2.7. Link Duration in Heterogeneous Environments 86 Chapter 4 Concluding Remarks 90 Future Work 91 Glossary and Notation 92 References 951193015 bytesapplication/pdfen-US移動模型移動無線隨意網路連線維持時間連線動態變化link durationlink dynamicsmobile ad hoc networkmobility model[SDGs]SDG7thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/53261/1/ntu-93-R91921029-1.pdf