Disclosed is a handover method in radio communication. A base station
apparatus monitors the receiving state of a terminal, detects, based upon
the receiving state, whether the terminal is one in which there is a
possibility that loss of a call or a decline in quality will occur or one
in which loss of a call or a decline in quality has occurred, and hands
over the terminal to another base station apparatus having a carrier
frequency different from that of the present base station apparatus.