無線感知網路(Cognitive Radio, CR) Technology為一創新的技術，其能有效率地提升計費頻帶的使用率。現存的計費頻道大多屬於多頻道的傳輸環境，而次級使用者(Secondary User, SU)如何在不影響優先使用者(Primary Users, PUs)的通訊之下，提昇計費頻道的利用率，將為本論文所要達到的目標。本論文擬在Cognitive Radio Networks (CRNs) 之環境中，提出一MAC通訊協定，稱為CS-MAC，其將解決SUs會面與頻寬資源浪費問題，使得各個SUs能在不影響PUs通訊的前提之下，進行資料傳輸。為了讓SUs能夠及時掌握PUs在計費頻道的通訊情況，本論文提出一Latin square based Sensing Schedule，讓任一個計費頻道在任一時間都有SUs進行頻道感測，並將感測結果傳送給擬傳送的SUs。實驗顯示，本論文的作法不僅能提昇計費頻帶的使用率，也能讓SUs掌握PUs在計費頻道的使用狀況。 Cognitive Radio (CR) Technology is an innovative technology for improving throughput of unlicensed band and the utilization of licensed band. To ensure that the licensed band can be fully utilized by SUs without interfering PUs, this paper proposes a cognitive radio MAC protocol, called CS-MAC which copes with the problems of rendezvous and packet collision. When the PU is detected, the proposed CS-MAC allows pair of SUs switches to another channel to continue the data exchange operation. A Latin Square based Sensing Schedule is further proposed to help SUs be timely aware the channel condition. Simulation results depicts that the proposed CS-MAC significantly improves the network performance in terms of the utilization of licensed bands and network throughput.
