以數值預測為基礎之隨機無線網路連線穩定與容錯研究

Numerical Estimation based Link Reliability with Fault Tolerance for Ad-Hoc Wireless Network

陳俊文(Chun-Wen Chen)

指導教授 ： 黃依賢

元智大學/資訊學院/資訊工程學系/碩士(2004年)

摘要

隨機無線網路是一個具有高度動態拓僕的暫時網路. 為了減少連線失敗造成的延遲與保證即時通訊的訊號品質, 一個以數值預測為基礎的連線穩定繞送(NELR)演算法含容錯機制在此被提出.在本論文中, 透過加權後的最小平方和逼近, 連線的訊號強度被模型成線性方程式. 因此連線的有效時間可以被精確的預測. 根據連線的有效時間與延遲時間, 最可靠的繞送路徑可以輕易的被尋獲. 容錯機制可以透過在連線中斷前重新找尋替代路徑來達成. NELR 是一個非常有效率且節省成本的演算法, 因為他不必依賴任何的定位系統或其他的基礎建設. 經過實驗, 顯示 NELR 增加了路徑的有效時間也增加了即時通訊的連線品質.

關鍵字

隨機無線網路 ； NELR 演算法 ； 容錯 ； 加權之最小平方逼近 ； 訊號強度

並列摘要

An ad-hoc wireless network is a temporary network with highly dynamic topology. In order to reduce the delay time caused by link failure and to insure the quality for real time communications, a numerical estimation based link-reliable routing (NELR) algorithm with fault tolerance is proposed. In this paper, each link’s signal strength has been modeled
as a linear function by using weighted least square approximation, and thus links’ life time can precisely be estimated. According to links’ life time and delay time, the most reliable path can easily be found. The fault tolerance can be achieved by replacing the instable path in time
before it breaks. The NELR algorithm is very cost-effective because neither location systems nor any infrastructure is required. Through simulations, it shows that the NELR algorithm increases the life time of path and improves the quality of service (QoS) for real time communications.

並列關鍵字

Ad-Hoc wireless network ； NELR algorithm ； Fault tolerance ； Weighted least square approximation ； Signal strength

參考文獻

[1] S.-J. Lee, W. Su; M. Gerla, ”Ad hoc Wireless Multicast with Mobility

Set Theory”. International Journal of Wireless Information Networks,

Adaptive Routing (SSA) for Ad Hoc Mobile Networks”, IEEE personal

IEEE International Conference on Universal Personal Communications,

(1995), 268-272.