A group is a collection of data objects that are same types of objects are grouped in one group and different types of objects are grouped in other group. The grouping is also called data segmentation. The sensor node is organized into groups. Within a group, nodes transmit data to Group Head (GH) without using Compressive Sensing (CS). Analytical model that represents the relationship between the size of groups and number of transmissions in the CS method, aiming at finding the optimal size of groups that can lead to minimum number of transmissions.