A wireless communication system and method for establishing and releasing a MAC entity. The system including a User Equipment (UE), having a first MAC entity for a first type of cell, for communicating with a first base station (BS) on the first type of cell; for establishing a second MAC entity for a second type of cell when communicating with a second BS while maintaining communication with the first BS; and for releasing the second MAC entity for the second type of cell when stopping communication with the second BS while maintaining communication with the first BS.