Patent ID: 8244254

Claim:
A mobile station capable of communicating with a first radio communication system in a communication system formed of the first radio communication system and a second radio communication system, the mobile station comprising: a communication unit configured to perform radio communication with a base station of the first radio communication system; a monitor configured to monitor a reception power of an interference signal that is transmitted using a frequency assigned to the second radio communication system and that interferes with the radio communication performed using a first frequency, wherein the monitor begins monitoring when the radio communication with the base station performed using the first frequency is interrupted; a notification unit configured to notify the base station of the reception power monitored by the monitor; and a handoff processor configured to perform handoff processing to switch the frequency used in the radio communication to a second frequency not interfered with by the interference signal in response to a handoff instruction transmitted by the base station having been notified of the reception power by the notification unit.