在IEEE 1609網絡中，即時交通資訊的散播是一個重要的應用服務，當一則交通資訊需要告知到某區域之行駛車輛時，不僅該地區的RSUs，而且該地區的OBUs，都需要協助廣播或轉送。在本文中，我們指出IEEE 1609網路中存在兩個重要的資訊散佈問題，第一個是週期不匹配的問題，第二是交易驅使消失的問題。接著，我們先提出了動態頻道切換協定來解決這些問題；進一步，我們再提出廣播後退計時器機制，來提昇動態頻道切換協定之效率，進而形成最佳之交通資訊散播演算法；最後，經由模擬驗證我們的結果並作出結論。

In IEEE 1609 networks, real-time traffic information dissemination is a critical application. Whenever apiece of information needs to be broadcast to vehicles within a specified range, not only RSUs in the range,but also most OBUs in the range, need to help broadcast/relay the information. In this paper, we identify outtwo problems existing in IEEE 1609 networks. The first one is the interval mismatch problem. The second isthe session driven disappearing problem. Then we propose the dynamic channel switching protocol to solvethese problems. Furthermore, we present the backoff timer mechanism to improve the performance of thedynamic channel switching protocol in order to form the best traffic information dissemination algorithm.Finally, we verify our results by simulations and make conclusions.