廣義的機會式通訊---無線行動網路中之競爭、合作與感知---子計畫三：感知無線行動網路之協力式擇路協定及服務品質控制

Abstract

隨著無線通訊技術與行動設備的快速發展，我們的日常生活中將存在各 式各樣的無線通訊網路。由於頻譜有限且大致都已被規劃分配，因此新興的 無線通訊網路勢必僅能被規劃於已分配的頻譜中進行無線傳輸。在頻譜重複 分配的環境中，如何規劃共享頻譜成為需要解決的重要問題。Cognitive Radio 為具有共享頻譜與協調無線傳輸行為的Radio 網路，其透過感測找出目前頻 譜的主要使用者，調整自己的傳輸特性，使得在不影響主要使用者的情況下 達到最大的頻譜利用率，降低相互干擾的程度。 本子計畫將考量在Homogeneous Network 與Heterogeneous Network 環境 中，於不同網路架構(PMP、Mesh 和Cluster)上，利用Cooperative 與Cognitive Radio 概念，研發增進頻譜利用以及提升整體網路效能的MAC 和Network Layer 機制與協定，其中包含Spectrum Sharing Scheduling 演算協定、Handoff 機制、Cluster Formation 演算法以及Multi-Hop Routing 協定。透過本計畫所 研發之MAC 和Network Layer 機制與協定，將可於不同的網路架構環境中更 進一步實現頻譜共享的概念，並在不影響原有通訊服務品質(Quality of Service, QoS)的情況下以Cooperative 的方式來增進頻譜利用，提昇整體網路效能與頻 譜共享效益。

Due to the rapid developments of wireless communication technologies and mobile devices, there are varieties of wireless communication networks in our daily life. Since the frequency spectrums are limited and have mostly been assigned to existing wireless communication networks, the emerging wireless networks will potentially be assigned with the overlapped spectrums. How to efficiently share the frequency spectrums becomes an important topic within the environment of overlapped spectrums. The Cognitive Radio (CR) represents a network of radios that coexists with higher priority primary users associating with secondary users. By sensing the presence of the primary users, the CRs can modify their own transmission characteristics in such a way that they will not create excessive harmful interference and consequently results in increased efficiency for spectrum sharing. In this project, the cognitive radio-based Medium Access Control (MAC) and the network layer protocols for the cooperative wireless networks will be proposed. Different network architectures, including the Point-to-Multipoint (PMP), the Mesh, and the Cluster structures, will be considered in both the homogeneous and the heterogeneous networks. The concepts of cooperative and cognitive radio will be utilized in the development of efficient MAC and routing protocols, including the QoS-based scheduling algorithms for spectrum sharing, the handoff mechanisms, the cluster formation algorithms, and the cooperative multi-hop routing protocols. The proposed MAC and network layer protocols can achieve the concept of spectrum sharing for the cooperative wireless networks. Without sacrificing the original spectrum utilization, the network performance can effectively be enhanced.