Patent ID: 8676204

Claim:
A mobile communication system comprising: a mobile station device; a first base station device configured to communicate with the mobile station device; and a second base station device which is registered in the mobile station device to access the second base station device, wherein the mobile station device is further configured to: detect that the mobile station device enters an area of a cell of the second base station device, transmit, to the first base station device, information of the cell of the second base station device includes a frequency of the second base station device, based on a list of the cell of the second base station device previously stored in the mobile station device in the case where both 1) the mobile station device detects that the mobile station device enters the area of the cell of the second base station device and 2) the mobile station device is not able to detect the cell of the second base station device, and the first base station device is further configured to perform searching for a presence of the cell of the second base station device based on the information of the cell of the second base station device to update control information required for the mobile station device to perform a measurement associated with the cell of the second base station device, wherein the information of the cell of the second base station device is at least used by the first base station device for searching for the presence of the cell of the second base station device and determining whether a gap is needed for the measurement.