中文说明：
针对QoS组播问题，本文采用粒子群算法，通过对算法的改进，使其能够应用到QoS组播路由问题上来，最终求出满足QoS约束的最小代价组播树。
English Description：
Aiming at the problem of QoS multicast, this paper uses particle swarm optimization algorithm, through the improvement of the algorithm, so that it can be applied to the problem of QoS multicast routing, and finally find the minimum cost multicast tree that meets the QoS constraints