Patent ID: 7787881

Claim:
A radio network controller, which reports a neighbor cell list, including information on neighbor cells which become candidates of a hard handover partner with frequency information to be used by respective neighbor cells, to a user equipment (UE) when a hard handover using different frequencies is performed in a mobile communication system, comprising: a frequency filtering controller which performs filtering processing to produce the neighbor cell list by using information on frequencies available for the user equipment, the information having been reported in advance by the user equipment as UE capability indication information, and use priority data on frequencies, so that a number of frequencies used by neighbor cells included in the neighbor cell list becomes equal to or less than a predetermined number; and a call controller which determines use priority of frequencies by loads of every frequency currently used in each cell to instruct the frequency filtering controller to perform filtering processing using the determined use priority of frequencies as the use priority data on frequencies, and reports the neighbor cell list, for which the frequency filtering controller has performed the filtering processing, to the user equipment; the call controller comprising: a compressed mode necessity judgment section which decides necessity of the compressed mode with reference to information on compressed mode necessity conditions included in the UE capability indication information in accordance with a combination of information on frequencies used by neighbor cells included in the neighbor cell list and information on a frequency currently used by the user equipment included in the UE capability indication information; and wherein the call controller gives instruction to the base station and the user equipment to activate a compressed mode only when the compressed mode necessity judgment section has decided the necessity of compressed mode in an operation of different frequency measurement performed by the user equipment.