The base station comprises a number of reach times judging section which judges
whether or not the number of times that the average radio resource usage volume
for a prescribed time period has reached a change threshold value during a prescribed
time period lies outside a reference number of times range; an allocation threshold
value increasing and decreasing section which increases the allocation threshold
value with respect to the radio resource usage volume at the time of a communications
request from a mobile station, if the number of reach times is less than the minimum
number of times of the reference number of times range, and reduces the allocation
threshold value, if the number of reach times is greater than the maximum number
of times of the reference number of times range; a usage volume at time of request
judging section for judging whether or not the radio resource usage volume at the
time of a communications request is less than an allocation threshold value; and
a radio resource allocating section for allocating a new radio resource in order
to establish a radio link with a mobile station, if the radio resource usage volume
at the time of the communications request is less than the allocation threshold value.
