無線技術的快速發展，行動用戶端隨時隨地的存取想要的資料。在無線環境之中，由於行動裝置頻寬的限制，所以廣播是一個用來節省頻寬的技術。在廣播通道的數量上，有單一通道與多通道之分別，而在多通道的廣播環境中，廣播資料可以平均分配到數個廣播通道中，如此可以減短廣播的週期，來減少用戶端存取資料的時間。當一個用戶端所請求的資料集合中，若資料集合被分配到不同的通道時，將可能發生存取的資料在相同時間廣播，這樣的情況稱為資料競爭。當發生此情形時，用戶端必須等待到下一個週期，如此便增加用戶端存取資料的時間。本文提出資料分割演算法應用在多通道上的資料分割，利用資料分割的結果，來減少在廣播排程上，用戶端請求資料所花費的廣播週期次數。最後針對我們所提出的方法進行效能的評估：比較初始化與使用本文所提出之演算法對於競爭次數的影響。實驗結果顯示本文所提出的演算法可以有效的減少資料競爭的發生。這樣的結果預期對用戶端在存取資料時可以有效地減少廣播週期的次數。 Owing to the advance of wireless communication techniques, a mobile user can access the desired data anytime anywhere. Due to the limit of mobile device, data broadcasting is an efficient method for save bandwidth. In the multi-channel, the data can be equally distributed to different channels for reduce the broadcast cycle and reduce the client which access data item. When a mobile user submits an issue for a data set that it distributed to different broadcast channels, the state called data competition. When the numbers of data competition increase, the data collision increase also, therefore, the mobile user must wait for next broadcast cycle, and thus the mobile user needs more time to access data set. The state called data collision. In this article, we propose the Two-Way Partition Algorithm and apply it to data partition of multi-channel. We use the result of data partition to reduce the data competition. Finally, we evaluate the performance of the algorithm and compare the data competition times that influence with initial states’ and using our algorithm. The result shows that our approach significantly reduces the data competition times.
