在本文中，我们设计，实施和实验性地评估可扩展定向多播（SDM）技术，以1）通过部分遍历码本树以每波束每客户端RSSI测量来训练接入点。培训平衡了收集足够数据以形成有效波束组的限制开销的目标。 2）利用可用的训练信息，设计了一种近似最小组播组数据传输时间的可扩展波束分组算法。(In this paper, we design, implement and experimentally evaluate scalable directional multicast (SDM) technology to train access points by partially traversing the codebook tree with RSSI measurements per beam per client. The training balanced the goal of collecting enough data to form the limiting cost for effective beam formation. 2) Using available training information, a scalable beam grouping algorithm with approximate minimum multicast group data transmission time is designed.)