摘要 |
There are provided a technology associated with a terminal device, a base station apparatus, a communication system, a communication method, and an integrated circuit, in all of which efficient communication control is performed. A terminal device makes a connection to a base station apparatus using a first cell group and second cell group, and, in a case where the second cell group that includes at least one cell is changed based on an information element which is notified with a radio resource control message that is received from the base station apparatus, starts counting of an RRC timer relating to a random access procedure for the cell in the second cell group, and initiates the random access. |