Improved algorithm to configure group number in group management MAC

Wireless sensor network becomes crucial with the appearance of the Internet of Things (IoT). IoT roots in the sensors' data and the technology to transmit the data to the sink. As the importance of IoT arises, the MAC protocols to transmit the data are proposed in many papers. Initially, the sensor devices and the sink remain stationary. As the technology has been advanced, the sensor devices start to move. Accordingly, novel protocols have been proposed for the changing topology. In this paper, we propose Improved-GM-MAC (I-GM-MAC), which means that new algorithms to reconfigure the group number and prevent the endless increasing of group number of the nodes in an isolated area are added to the 3-dimensional group management MAC (3D-GM-MAC).