利用合作臨機路由增進多跳躍無線網狀網路之效能

Abstract

多跳躍無線網狀網路的架構設計提供普及的無線存取服務。近年來如何有效傳輸多跳躍網狀網路之頻寬資源，以及利用臨機路由來增進網路效能，已受到諸多的關注。在多跳躍無線網狀網路中，傳輸穩定性與封包遺失交互影響並決定網狀網路之傳輸量。目前已有文獻指出同時解決傳輸穩定性與封包遺失問題，可以使網狀網路達到較高傳輸量的效能。雖然已經有非常多學術論文致力於解決網狀網路中之傳輸穩定性與封包遺失問題，但其中大多數都忽略了網路中重複傳送之成本，亦或假設使用傳送資料表(forwarding list)來傳輸資料。在本篇論文中，我們將討論以最小花費回饋上游目前評估之傳輸成本的方法，以及提出利用回饋訊號的傳輸策略以避免封包重複傳送和封包遺失。接著，我們會結合上述的兩個機制，提出一個新的合作臨機路由。藉由OMNet++進行模擬驗證。

The architecture of Multi-hop wireless mesh networks (WMNs) provides widespread wireless access services. In recent years, much attention has been paid to the problem of the efficient transmission in multi-hop mesh networks, and the network performance with opportunistic routing. In multi-hop WMNs, the transmission stability interacted with packet loss ratio determines the transmission throughput. Recent studies have shown that the performance of higher throughput can be achieved while addressing both the transmission stability and packet loss problems. Although there are many papers dedicated to solve those problem, most of them have ignored the repeated transmission cost, or assumed that the forwarding list is used to transmit data. In this dissertation, we first discuss the methods to assess the minimum transmission cost of the current networks. Then, we propose a strategy which requires acknowledge signal to avoid duplicated transmission and packet loss. Moreover, we combine the above two mechanisms and propose a new cooperative opportunistic routing mechanism. Our experimental results are simulated and verified on OMNet++.