在無線感知網路（Cognitive radio networks）中，次要使用者(Secondary user)必須保證在不干擾合法使用者的情況下使用已被註冊的頻譜，因此，保護合法使用者是無線感知網路的第一考慮因素。然而，在無線感知網路中，主要使用者的接收端因為不會發出訊號，因此，不容易被次要使用者偵測。為了保護主要使用者的傳輸，次要使用者需要繞開主要使用者的傳輸範圍已達完全的保護。因此，我們必須要在傳輸延遲及對主要使用者的傳輸取得平衡。我們考量感測主要使用者的使用情形，並透過動態的選取下一步節點，達到保護主要使用者傳輸權益並且同時能夠傳遞次要使用者的資料。相比於已有的研究，我們提出了在保護主要使用者的前提下，縮小次要使用者的傳輸時間。Cognitive Radio (CR) technology aims to enhance spectrum utilization in the licensed bands with a non-intrusive manner. Therefore, protecting primary user from interference is considered as the first priority. However, it incurs the trade-off in CR networks performance. In order to evaluate this trade-off, a distributed routing protocol for CR ad hoc network is proposed that makes the following contributions: (i) full figuratively protection for PU receiver which is generally hard to be detected, (ii) allowing selecting next hop locally and dynamically without reserved all along the path to destination, and (iii) scalable, joint route-spectrum selection. A key innovation of our work is proposing the way to select next hop without harming PU activity at the same time can reduce latency delay caused by PU sudden appearance. Result displays the importance of developing the routing algorithm with the viewpoint of safeguarding the PU communication, which is also the unique feature in CR networks.
