A CDMA mobile communication system carries out a method of controlling an
intersystem hand-off by subtracting a margin value from a pilot signal
strength of another system. A detector detects information in a report
from the mobile station, representing the signal strength of the pilot
signal from the base station. A changer subtracts a corresponding margin
value from the detected pilot signal strength, thereby changing the pilot
signal strength. The executing unit executes an intersystem hand-off to
the other system if the pilot signal strength changed by the changing
means exceeds a predetermined threshold value.
