近幾年來，隨著無線網路上及時性應用程式的增加，提供服務品質給即時性的資料流漸漸的引起大家的注意。然而，IEEE 802.11無線網路環境下最普遍的通訊協定-分散式協調函式（DCF）卻沒有提供服務品質的機制。另一方面，無線網路所展現的一些獨特的特性，像是完全分散式的環境、空間競爭性、以及多點轉送的交通型態，更讓提供服務品質的任務增加了許多挑戰性。

　　在論文中，我們考慮了上述的一些無線網路的特性，提出一種分散式的封包排程演算法。首先，我們利用資料封包來背負一些控制訊息，並啟動雜亂監聽模式來將一個無線節點中最前線封包的的傳送截止時間傳播給空間中其他的無線節點，進而發展出一套藉由比較各節點傳送截止時間的緩急程度來調整節點後退時間，繼而決定封包傳送優先權的機制。另一方面，我們注意到一個在無線網路上相當獨特，稱為自我偶合的問題，並特別設計了此一問題的解決方案，冀以消除在同一個資料流中，各個節點盲目競爭的現象。我們相信，藉由我們所提出的機制來考慮各節點的傳送優先權及協調無線節點接的空間競爭行為，我們可以達到更加的端對端傳輸延遲及更高的封包傳送率來滿足服務品質的要求。

　　In the recent years, more and more attention has been attracted to providing quality of service (QoS) for real-time traffic in wireless ad hoc networks as the increase of real-time applications. However, the Distributed Coordination Function (DCF), the popular communication protocol in IEEE 802.11 standard, fails to provide QoS guarantee for real-time applications. On the other hand, some characteristics in wireless network, such as fully distributed nature, spatial contention, and multi-hop environment, make QoS-supporting considerably a challenging job.

　　In this thesis, we propose a novel distributed traffic scheduling scheme by considering some special characteristics of wireless ad hoc networks mentioned above. In our scheme, we take advantage of a piggyback in data packets and the promiscuous mode in wireless networks to spread the timing information of head-of-line (HOL) packets among several nodes who share a common channel in a standpoint of spatial contention. A backoff time adjustment policy is developed to coordinate the transmission orders of these contending nodes in accordance with the urgency of their packets. Besides, we address a special phenomenon in wireless ad hoc network called self-coupling problem and design an effective solution to eliminate the blind contentions within a flow. By well-coordination of spatial contention with consideration of priority of each packet, both average end-to-end delay and the packet delivery ratio can be significantly improved so that the QoS condition can be satisfied as far as possible

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