Patent ID: 8831620

Claim:
A communication method in a mobile communication system including a macro Advanced Base Station (ABS), one or more femto ABSs, and one or more Advanced Mobile Stations (AMSs), the communication method comprising: broadcasting, by a specific femto ABS of the one or more femto ABSs, cell type information indicating that the specific femto ABS is being operated as a Closed Subscriber Group (CSG) femto ABS instead of an Open Subscriber Group (OSG) femto ABS, and the CSG femto ABS is being operated as a first type CSG femto ABS from among the first type CSG femto ABS and a second type CSG femto ABS, the first type CSG femto ABS and the second type CSG femto ABS being classified by accessibility of non-member AMSs to the specific femto ABS; converting, by the specific femto ABS, the specific femto ABS from the first type CSG femto ABS to the second type CSG femto ABS under a specific condition; and transmitting, by the specific femto ABS to at least one of the one or more AMSs, a signal including changed cell type information indicating that the specific femto ABS has changed from the first type CSG femto ABS to the second type CSG femto ABS, wherein the changed cell type information is included in a preamble, and wherein the specific condition comprises: reception, by the specific femto ABS from a non-member AMS of the specific femto ABS that undergoes interference by the specific femto ABS, of a ranging request message that includes an indicator requesting interference mitigation, or reception, by the specific femto ABS from the macro ABS, of type change request information or interference mitigation information for the non-member AMS of the specific femto ABS that undergoes interference by the specific femto ABS.