無線隨意網路是由行動裝置而構成自律分散式的網路，行動裝置靠著之間的互相合作來傳遞封包，但行動裝置會因自身有限的資源例如電力，產生是否轉送源自其他裝置封包的自私行為，而這種自私節點的行為會降低封包的成功傳遞量，所以自私節點的出現成為一項值得探討的研究議題。
近幾年的研究中，數種偵測自私節點的方法被陸續提出，但這些方法通常都假設自私節點在隨意網路下是少數的，並且都被當成惡意節點而發展出一機制偵測及隔離；本研究認為自私並非一種惡意行為，而是每一個行動裝置皆會出現的自然行為，所以本研究探討分析在隨意網路的節點全都為自私節點時所造成之效能影響，並在每一個自私節點上加入友誼 (Friendship)機制，節點與節點藉由朋友之間的信任來傳遞封包以提升整個網路效能。

A MANET is a self-organizing and self-configuring network without the need for any existing network infrastructure or centralized administration. A MANET is a collection of mobile nodes with limited resources such as battery power. Limited resources make the nodes appear selfish behavior. Selfish nodes want to save their resources for their own usage, so they are unwilling to spend resources to forward data packets. In consequence, selfish nodes will reduce the total packet delivery ratio in a MANET. Every node may appear selfish behaviors in real world environment. In the previous published literature, the general assumption is that only a few selfish nodes in a MANET. Selfish nodes usually are viewed as malicious nodes, and detection mechanisms are developed to identify and isolate node with malicious behaviors.
In this study, the author argues that selfishness is not a malicious behavior. Actually, selfishness is a natural behavior for all nodes in the MANET. Thus, this study is to measure and evaluate the possible effects in the real world where all mobile devices are selfish nodes and proposes a friendship strategy for each selfish node is developed to observe and evaluate performance improvement in a MANET.

中文摘要 i
ABSTRACT ii
誌謝 iii
CONTENTS iv
List of Figures v
List of Tables vi
Chapter 1 Introduction 1
Chapter 2 Related Works 4
2.1. The DSR protocol 4
2.2. Existing Solutions of Selfish Nodes in MANET 6
Chapter 3 Friendship Strategy for Selfishness in MANET 11
3.1. Modeling the Behavior of Selfish Nodes 11
3.2. Friendship Strategy 13
Chapter 4 Simulation Result 15
4.1. Simulation Scenario 15
4.2. Performance Analysis 17
4.2.1. The Throughput 18
4.2.2. Packet Delivery Ratio 23
4.2.3. Average End-to-End Delay 27
Chapter 5 Conclusion 31
References 33

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