在這篇論文中，我們研究超寬頻網路（Ultra-Wideband, UWB）的效能。超寬頻網路使用集中控管的方式，在MAC 層將來自上層的封包集合組成一個大的超訊框(superframe)，並且由管理站台統一分配每個站台的傳送時間。為了降低同步所需花費的同步時間的影響，我們採取多通道系統的做法，其中多通道系統的概念是允許系統利用不同通道在相同時間傳出多個封包。為了解決站台在傳送端及/或接收端的碰撞問題，也為了充分利用通道資源，我們提出一個容易實現而且表現良好的多通道封包排程演算法。在各種封包到達率與通道數量之下，我們比較各種排程演算法的平均封包延遲，成功送達率，通道使用率，時槽使用率以及封包遺失機率。透過與先前提出之封包排程演算法之比較，我們顯示所提出之封包排程演算法優於其他封包排程演算法。在我們模擬的環境中，封包到達採用波以松(Poisson)流量模型。另外考慮到目前多媒體的風行，我們也考慮具有四種服務等級之情境，並以優先權的方式來實現服務品質的分級。我們顯示，無論是同質或異質流量情境，所提出的封包排程演算法均可提供效能之改良。

In this thesis, we study the performance of the Ultra-Wideband (UWB) networks. UWB networks are based on a centralized control topology, where at the MAC layer it collects the packets from the upper layer to form a superframe, and the controller node is responsible for allocating the transmission time of each node. In order to reduce the synchronization overhead caused by the acquisition time, we adopt the concept of the multiple-channel system. The concept of the multiple-channel system is allowing the system to transmit multiple packets at the same time on multiple channels. To resolve the collisions occurring at transmitting and/or receiving nodes, and to utilize the bandwidth efficiently, we propose a multiple-channel packet scheduling algorithm, which can be implemented easily and perform well. Under various packet arrival rates and numbers of channels, we compare the performances of various packet scheduling algorithms in terms of average packet delay, throughput, channel efficiency, slot efficiency and packet dropping probability. It is shown that the proposed packet scheduling algorithm outperforms the other algorithms. In our simulation environment, the packet arrivals are modeled as a Poisson arrival process. With the current popularity of multimedia services, we also consider the scenarios with four service categories, and prioritization is used to achieve differentiation of quality of service (QoS). We show that the proposed packet scheduling algorithm does improve the performance, no matter the traffic is homogeneous or heterogeneous.

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