本論文討論於WiMAX網路中提供IPTV服務之群播資源分配問題，並加入子通道品質的考量。不同於以往相關研究在資源分配上單純以系統的角度作為考量，本論文設計一由使用者角度考量之使用者滿意度評估方式，同時為了能夠兼顧系統獲益以及使用者之滿意度，設計一系統效能指標。在資源分配方面，本論文利用對群播組的切割，將群播組中訊號品質較差之使用者切割出來，置於其可支援較好調變之子通道上傳送，對瓶頸使用者與其餘使用者皆提升調變，減少資源消耗，提升整體系統效能以及頻寬資源利用率。 模擬結果顯示，本論文提出之群播分組與資源分配機制與以往相關研究相比，在Base Layer能夠有效的減少資源消耗，因此在資源有限的情況下，可服務更多的Enhancement Layer使用者，可得到較高之系統獲益以及使用者滿意度。 This paper investigates multicast resource allocation problem for IPTV services in WiMAX networks and proposes a subchannel-aware IPTV multicast grouping and resource allocation mechanisms (MGRAM) for bandwidth utilization improvement. In the proposed mechanism, both system profits and user satisfactions are considered to form a system performance weight for multicast group partition and resource allocation. In multicast group partition, this paper separates users with bad subchannel conditions from the original multicast group, which is grouped based on the subscriptions of programs, into a new multicast group. Therefore, multicast group partition can promote available modulation to improve bandwidth utilization. Based on the results of the multicast group partition, each multicast group is allocated based on the system performance weight. Besides, this paper conducts a simulation to evaluate the performance of the proposed mechanism. Simulation results show that MGRAM obviously outperforms the related work in user satisfactions and system profits when the number of users increases in the networks.
