Abstract
Now voice conference is popular in society. How to construct conference tree efficiently becomes a very important discussion. Our research is focus on this topic. Consider in a multiparty conference, we assume each edge has edge cost, each node has mixer cost, and each node has degree constraint. First, we prove this problem is NP-complete problem. Then we show the importance of mixer cost. The major consideration of constructing a spanning tree is minimizing conference tree total cost. Our research provide three efficient algorithms to construct multicast tree, First-time least 3-node-cost first、Least 3-node-cost first、and Improved least 3-node-cost first. Improved least 3-node-cost first is the best in our experiments. Finally, we will have some simulations. We compare our methods to other methods to show our methods are more efficient than other methods.