近年來由於無線網路技術的快速發展,使得無線網路的傳輸速度與傳輸距離都有相當大 的改善。雖然仍無法達到傳統有線網路的傳輸速度,但由於無線網路具有可移動性與較 低建置成本的特性,使得愈來愈多的應用在無線網路進行,帶來更多的便利性。而WiMax 是近年來新興的「無線寬頻」技術之一,其擁有高頻寬與長距離的特性,可以用來解決 都會網路「最後一哩」(Last Mile)的問題。因WiMax所具有的特性,所以可以廣泛應用 在許多相關的領域中。然而,當大量的使用者使用行動裝置來收發資訊或是分享影音及 數位學習時,極容易因大量的訊息廣播而造成訊號之間的互相干擾並導致通訊訊號不穩 定及廣播風暴(Broadcast Storm)的情況發生。而造成這些問題發生的主要原因,就是爭 奪WiMax最關鍵的資源---通訊頻寬。為解決通訊頻寬爭奪的問題,本研究提出頻道分配 機制(Channel Allocation)與碰撞排除機制(Interference Aware),減少因訊息廣播而 產生的封包碰撞(Collision)及行動設備電力快速消耗等問題,藉此使網路的傳輸更具穩 定性,並增加資源的有效再利用,以提升傳輸效能與降低傳輸時間。
In recent year, the rapid growth of wireless communication technology improves the transmission data rate and communication distance. Although the transmission rate of wireless network still cannot catch up with the cable one, there are still increasingly applications on wireless network due to its features of mobility and low setup cost. WiMax is the one of new broadband wireless technologies. It can solve the last mile problem of the metropolitan network because of the features of high bandwidth and long distance.Owing to the features of WiMax, it can be extensively applied to various related fields. However, if large amount of users use these applications, it may occur transmission collision and broadcast storm. The most important factor to cause this problem is the competition of communication bandwidth by different service requests.In this research, two methods are proposed which are channel allocation mechanism and interference aware method to solve the problem. The interference aware method will assist to channel allocation mechanism enhances the utilization of resource and shortens the time of transmission.