1. A method of reporting mobility state information performed by user equipment (UE) in a wireless communication system, the method comprising: estimating, by the UE, a mobility state of the UE, wherein the mobility state is one of a normal mobility state, a medium mobility state, or a high mobility state; determining, by the UE, a mobility group state of the mobility state, wherein the mobility group state is one of a first mobility group state or a second mobility group state; and reporting, by the UE, mobility state information for the mobility group state to a network, wherein the mobility state is estimated based on a number of cell movements performed by the UE during a specific time interval on a basis of a Mobility State Estimation (MSE).