行動隨意網路的運作需要依賴各個節點之間的互相配合以達到能夠彼此通訊的目的。然而，現實生活中的網路節點卻有可能為了保留行動裝置所需的電池能量、減少佔用的記憶體空間及降低處理器運算時所需消耗的週期時間等利已的理由而不願意正常執行遞送封包的任務，造成網路效能大幅地下降。為了減輕這些因為自私節點的存在所造成網路效能低落的缺點，本論文提出了一個以合作為導向的協同名聲機制，稱之為協同代理人名聲系統。此系統包含有三個主要的技術，第一，為了了解鄰近節點在封包傳輸上的行為表現而利用名聲機制來偵測自私行為的存在並作適當的回應。第二，相較於以往名聲機制的相關研究只能使用DSR，本論文提出指定代理人機制為資料封包的傳輸尋找另一條更穩定的替代路徑並使之能夠適用於AODV及DSR等在行動隨意網路上常見的路由協定。第三，由於無線傳輸可能因為地理環境或傳輸介質的差異而造成名聲機制在判斷上的失誤，因此為了能夠彌補這判斷上的缺失以及增進網路的互連性，名聲贖回機制允許適時地恢復原自私節點在網路上的使用權以期能夠增進網路上各節點之間的互連性並使得網路效能得以增加。本論文將使用Qualnet網路模擬器來加以驗證協同代理人機制的高效率及有效性。

In a Mobile Ad hoc NETwork (MANET), node cooperation in routing and packet forwarding is essential for the network to operate properly. However, in order to save resources (e.g., energy, memory, CPU cycles and so forth), some misbehaving nodes might not intend to forward packets, which significantly degrade the network performance. To cope with such misbehavior phenomena in MANET, this thesis proposes a cooperation-agent reputation system, designated as Co-Agent, which consists of three schemes designed specifically to detect and avoid selfish nodes for mitigating the effect of routing misbehavior, to designate agents for finding an alternative route in the present of selfish nodes, and to allow misjudged nodes which have been isolated from the network to redeem their reputation and rejoin the network. Unlike current proposed schemes in the literature which only support the DSR routing, Co-Agent can be applied in both DSR and AODV routing mechanisms. The proposed mechanism is implemented in the Qualnet simulation environment. Simulation results confirm the proposed Co-Agent mechanism has improved the network throughput significantly.

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