網路會為群播服務建立一棵樹使得重複性資料可以減少, 但是一旦網路節點或傳輸線出現問題, 下游節點無法再繼續接收資料, 因此如何維持群播服務之品質是一重要之問題。本篇論文提出一種固定最小群播樹演算法去建立備用之群播樹, 此樹可以有效的解決網路中嚴重之損壞並即刻修復。此備用之群播樹建立方法是根據統計方法。模擬結果顯示此備用之群播樹可有效提高群播可靠度。 In a backbone network, a steiner multicast tree (SMT) will be established for multicast members to minimize the traffic load on network. However, a link or node may be failure by some accidental factors during transmission period. Downstream nodes respect to the failure link/node will be forced to leave this tree. To guarantee the quality of service (QoS), it is desirable to have some schemes for the multicast tree so that such termination can be avoided or at least, reduced. In this paper, we propose a fixed SMT algorithm (FSA) to construct the steiner backup multicast tree (SBMT). Based on FSA, for each 'critical' path, an alternate route with enough bandwidth will be reserved such that most fatal failures in network can be recovered immediately. The way to determine critical paths is based on the statistical analysis. The adjustment of the SMBT when nodes dynamically join or leave the SMT is also discussed. The degree of fault tolerance of proposed strategy is evaluated by simulation. Simulation results demonstrate that FAS improve the reliability.
一九九八年全國電信研討會論文集=Proceedings of 1998 National Symposium on Telecommunications，頁46-51