Patent ID: 8583121
Filing Date: 2013-11-12
Classification: H04W

Abstract:
1. A mobile communication system comprising: a first radio apparatus which defines a first cell; and a second radio apparatus which defines a second cell that covers an area at least a portion of which overlaps an area that the first cell covers, wherein when it is determined by the first or second radio apparatus that communication conditions of a first mobile station currently radio-linked to the first or second radio apparatus have degraded, then the first radio apparatus stores identification information of a second mobile station that belongs to the first cell and that is currently radio-linked to the first radio apparatus, and causes the second mobile station to hand over to the second cell, changes a first radio frequency currently used in the first cell to a second radio frequency that is different from the first radio frequency, and sends the second radio apparatus a message that carries identification information of the second mobile station and information indicating the second radio frequency, and wherein when the message is received, the second radio apparatus notifies the second mobile station identified by the identification information carried in the message of the second radio frequency, and causes the second mobile station to hand over to the first cell, and wherein the first or second radio apparatus determines that the communication conditions have degraded, when a radiowave quality value indicated by a signal which is received from the first mobile station and indicates the quality of a radiowave received at the first mobile station is lower than a certain radiowave quality value.