In this paper, we present and visit the limitation of reference point group mobility model. It assumes that nodes in the same group always stay together throughout the simulation process. However, in many real life applications, the nodes’s movement within a group is not always common. In particular, in a military operation, initially there is only one group. With multiple missions assigned to it, the group may be divided into a number of subgroups with each subgroup moving to a different location for accomplishing its task. A subgroup may be further divided into smaller groups or merge with other subgroups after completing its task. In the urban environment, the convoys of cars running on the street can split at the intersections. Therefore, in many real life scenarios mobile nodes (MNs) dynamically re-configure themselves triggering group partition and mergence; MNs sometimes merge and move together and sometimes split and move individually and independently. Some recent researches present mobility models such as reference region group mobility model or virtual track based group mobility model, which model possible group partitioning and group merging. We call this kind of mobility models group merge and split mobility models.