近年來，隨著無線網路通訊技術的快速發展和行動通訊設備的普及，行動即時影音群播服務如IPTV或串流影音等群播服務也愈來愈受到重視。相較於IEEE 802.16d而言， IEEE 802.16e / 802.16j將移動性納入考量，並具有高速率、遠距離傳輸之傳輸特性，如何提供行動使用者兼具省電及品質保證之多媒體群播服務已成為現今最熱門研究主題之一。群播較多次單播可節省大量頻寬，獲得群播效益，但群播效益的產生需要各個MS共同醒來，以相同的速率接收來自BS的影音群播資訊，因此明顯與睡眠效益相衝突，本論文將研發具電量知覺的群播技術，使BS獲得群播效益的同時，仍能讓電量較弱的MS獲得較佳的睡眠效益，並對影音傳輸的QoS有所保證。最後，我們將以NCTUns來進行模擬，以驗證我們所研發的群播技術在群播效益、QoS、省電效益的表現效能。 The mobile WiMAX networks characterized by the long-haul communications and high-speed transmissions have attracted researchers to develop multicast scheme for supporting the wireless video services, such as mobile IPTV. As compared with unicasting data to mobile subscriber (MS) one by one, the multicasting can save the bandwidth consumption and thus gains the multicast advantages. However, all MSs in the multicast group should cooperate with each other to wake up at the same time for receiving the multicast data. Hence the level of power saving might be reduced. In addition, delay constraint of some MSs might not be guaranteed since these MSs might apply the lower modulation rate to accomplish the multicast service with the other MSs. This paper proposes an efficient QoS-guaranteed and energy-aware multicasting mechanism. The proposed mechanism aims to maximize the multicast advantages of the BS and guarantee the delay constraint of each MS while the MSs with lower battery life can save more energy. Simulation results reveal that the proposed QEM2 multicast mechanism outperforms existing work in terms of the multicast advantages, user satisfactory and energy saving.
