在微波接取全球互通(WiMAX)網路的網路電視(IPTV)群播排程設計

Abstract

在無線網路普及的現在，WiMAX被視為下一代熱門的技術，在政府釋出WiMAX頻譜使用執照後，WiMAX將會與現今使用的WiFi與3G網路共同建構出無縫(seamless)的網路，讓使用者可以隨時隨地連接網路，可以在較便宜的價格中很便利性的連接網路；而網路電視(Internet protocol television)將在無線網路普及的情況下，成為殺手應用服務，能為系統服務提供者增進可觀利潤，也能為使用者提供更方便且便宜的電視節目收視選擇，但現今較少研究者對影音多媒體資料在WiMAX的傳播排程研究，我們著眼於此，提出適合的群播排程演算法，使得影音串流資料在WiMAX的傳遞可以保證無線網路資源分配的加權公平分配(Weighted time fairness)、通道調整設計(Channel-aware design)可得到高傳輸率(throughput)、保證影像品質的畫框優先權傳送(Frame priority transmission)，提高其QoS。並具有跨階層設計，將影像編碼與解碼的應用層(Application layer)、群播排程演算法的媒體存取控制層(MAC layer)、可變資料傳輸率(multi-rate)的實體層(Physical layer)來進行最佳化，讓使用者收視時可以保有良好的影音品質，享受網路電視所帶來的休閒娛樂。

Currently, all kinds of the wireless access networks are in widespread use. Among them, the WiMAX is regarded as the popular technology of the next generation. After the government releases the WiMAX spectrum licenses, the WiMAX will construct a seamless access networks with presently used wireless network of the WiFi and third-generation (3G). It will enable users to connect to the networks anywhere and anytime, and provide convenient access the networks in a cheaper price. With popular wireless network, the Internet protocol television (IPTV) will become killer application, providing considerable profits for the system service provider along with easy and cheap television programs accesses for the users. However, there are few researcher has studying the multimedia multicast scheduling in the WiMAX networks recently. Focusing on this point, we proposed a suitable multicast scheduling algorithm in the WiMAX networks. It makes the transmission of video streaming data in WiMAX wireless network guarantee radio resource management with weighted time fairness, higher throughput with our Channel-Aware design, frame priority transmission, guaranteed delay bound, reduced jitter and enhancements in its QoS. Besides, our scheduling algorithm has the cross-layer design. It can do optimization according to different layer information including video encoding and decoding from the Application layer, multicast scheduling algorithm from the Medium Access Control layer, adaptive date rate control from the Physical layer. It can enable users to watch television programs with good video quality and enjoy the entertainment that the IPTV brings.