A method is disclosed that is capable of appropriately assigning radio
resource even when a propagation quality changes. After receiving the
required communication rate from the mobile station, the base station
measures the maximum used radio resource, and multiplies the maximum used
radio resource by a factor .alpha.. Next, the base station subtracts the
above result from the total radio resource and obtains the maximum
assignable radio resource. Then, the base station calculates an
admissible communication rate based on the maximum assignable radio
resources. Then, if the required communication rate is less than or equal
to the admissible communication rate, the base station admits the
request.