近年來，以802.11技術為主的『無線網狀網路( wireless mesh network,WMN)』逐漸受到大家重視。然而，由於802.11 DCF 採用隨機競爭存取的方式，會在網狀網路環境下造成大量的碰撞，使得throughput降低的非常嚴重。本篇論文的貢獻便是修改802.11 DCF機制，而發展出了一套適用於無線網狀網路的分散式媒介存取協定-『漣波協定(Ripple protocol)』，相對於現有的802.11 DCF隨機存取機制，漣波協定採用受控型(controlled)存取機制以避免不必要的封包碰撞並運用空間重覆利用(spatial reuse)提昇網路整體效能。在本論文中，我們也進一步提出了一個數學模型以分析漣波協定的效能，並利用系統模擬的方式驗證了分析的正確性。此外，也將漣波協定的效能與802.11 DCF相比較，結果顯示採用漣波協定將可使網路的效能提升了2~3倍。

Wireless mesh network (WMN) is a novel wireless broadband access technology
which is currently attracting significant attention. The contention-based 802.11 DCF may not be suitable for WMNs. The throughput will decrease seriously due to the random access approaches. This thesis proposes a distributed medium access protocol, named Ripple, for wireless mesh networks (WMNs). In contrast to existing random access approaches, Ripple employs a controlled access mechanism to protect nodes from unintentional packet collisions and maximize the spatial reuse. Thus, the throughput of WMN is significantly improved compared with the 802.11 DCF method. An analytical model is further proposed to determine the performance of the Ripple protocol and the accuracy of the analysis is verified via simulation. Simulation results demonstrate that Ripple protocol doubles the network throughput than that of the 802.11 DCF method.

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