A radio-parameter control method allowing fine radio-parameter setting to
improve communication quality is disclosed. Fixed stations are
distributed at predetermined locations in a service area. A fixed station
monitors reception condition of a pilot channel signal and transmits the
monitored condition data back to a corresponding base station. A radio
network control station statistically analyzes the monitored condition
for each fixed station and estimates a future location of a mobile
station. Radio parameters for use in radio communication between the
mobile station and a base station corresponding to the future location of
the mobile station are controlled based on statistical condition data at
the future location of the mobile station.