Wireless sensor networks (WSNs) are an important component of the Internet of Things (IoT). Each multicast group in a WSN consists of a set of multicast members. In a sparse network, multicast members belonging to the same group may not be very closely spaced. On the other hand, in a dense environment, more than one multicast member of a group may highly reside within downlink regions of the same router which may or may not be a multicast member. In that case, a multicast message can be delivered to more than one multicast member in a shot. This characteristic improves the status of a node from an ordinary router to a topological kingpin. If a good number of topological kingpins are included in a multicast tree, then a great amount of energy is saved increasing network throughput. The present article proposes one such energy efficient multicast scheme: Smart–Green–Mult (SGM), based on Software Defined Wireless Sensor Network (SD-WSN) framework. The network is divided into several zones. The shape of each zone is either circular or elliptical or polygonal. Each zone is under control of an Software Defined Network controller. SDN controller of each zone is aware of the topology of the zone and can compute energy efficient paths from any source to any destination inside or outside the zone. Overall this is a multicast protocol in SD-WSN.

无线传感器网络（WSN）是物联网（IoT）的重要组成部分。WSN中的每个多播组均由一组多播成员组成。在稀疏网络中，属于同一组的多播成员可能不会间隔很近。另一方面，在密集环境中，组中的一个以上多播成员可能高度驻留在同一路由器的下行链路区域内，该路由器可能是也可能不是多播成员。在那种情况下，多播消息可以一次发送到一个以上的多播成员。此特性改善了从普通路由器到拓扑主销的节点状态。如果多播树中包含大量拓扑主干，则可以节省大量能量，从而提高网络吞吐量。本文提出了一种这样的节能多播方案：基于软件定义的无线传感器网络（SD-WSN）框架的Smart-Green-Mult（SGM）。网络分为几个区域。每个区域的形状可以是圆形，椭圆形或多边形。每个区域均受软件定义的网络控制器的控制。每个区域的SDN控制器都知道该区域的拓扑，并且可以计算从任何源到该区域内外的任何目的地的节能路径。总的来说，这是SD-WSN中的多播协议。每个区域的SDN控制器都知道该区域的拓扑，并且可以计算从任何来源到该区域内外的任何目的地的节能路径。总体而言，这是SD-WSN中的多播协议。每个区域的SDN控制器都知道该区域的拓扑，并且可以计算从任何来源到区域内外的任何目的地的节能路径。总的来说，这是SD-WSN中的多播协议。