無線隨意網路下具省電功能的排程機制

Abstract

在無線隨意網路中，電力是有限的。而網路的存活時間深深地受到電力消耗快慢的影響。當電力消耗減少時，網路的存活時間會隨著延長。因此，如何減少電力的消耗便成為無線隨意網路領域中一個重要的目標。為了達成這個目標，各種調整電力參數的省電演算法相繼被提出。在現實世界中，傳送一個封包的電力消耗會隨著時間改變。換句話說，節點傳送封包的順序對該節點的電力消耗會造成影響。 在本篇論文中，我們提出一個具省電功能的排程機制，稱之為『具省電功能的開始時間戳記公平排程演算法 (Power Saving Start-time Fair Queuing，PSSFQ)』。我們從調整封包傳送順序的觀點來達到省電的目的。此演算法的構想是要找出電力消耗最小的封包傳送順序。我們將上述的構想加在現存的公平排程機制上。『開始時間戳記的公平排程演算法 (Start-time Fair Queuing，SFQ)』被選定為我們的基礎演算法。 我們透過模擬來評估此演算法的效能。模擬結果顯示對於封包傳送順序最佳化可以減少傳送時的電力消耗。

Power is the limited resource in the ad hoc network. The network life is deeply affected by the power consumption of nodes. As long as the power consumption decreases, the network life extends. Thus, the way to reduce the power consumption becomes an important objective in the ad hoc network domain. To reach this objective, various power-saving algorithms are proposed in the direction of adjusting the power factors. On the other hand, these algorithms don’t consider about the sending sequence of the packets. In the real world, the power consumption of transmitting a packet may vary by time. In other words, the packet deliver sequence may affect the power consumption of sending a packet. In this essay, we proposed a fair queuing algorithm with power saving, as known as Power Saving Start-time Fair Queuing (PSSFQ). We reach the goal of power saving with the respect of resorting the packet deliver sequence. The conception of our proposed algorithm is to find out the packet deliver sequence with the minimum power consumption. We practice the conception by modifying the existing fair queuing algorithm. The Start-time Fair Queuing (SFQ) is chose as our base algorithm. We evaluate the performance of the proposed algorithm by simulations. The result shows that the consideration of the packet deliver sequence can reduce the power consumption of transmission.