Method for controlling overload in digital mobile communication system

1. A method for controlling an overload of a digital mobile communication system having a base transceiver station and a base station controller, wherein each of the base transceiver station and the base station controller has a database, the method comprising the steps of:

a) initializing threshold values stored on the database as predetermined values;

b) monitoring each of utility rates of a control processor resource and a call resource;

c) comparing the utility rates of the control processor resource and the call resource with the threshold values respectively, thereby obtaining overload grades of the control processor resource and the call resource;

d) comparing the overload grade of the control processor resource with the overload grade of the call resource, thereby selecting one of the control processor resource and the call resource as a resource to be controlled, which has a higher overload grade;

e) determining whether an overload occurs in the resource to be controlled;

f) if the overload occurs in the resource to be controlled, informing a base station manager of an occurrence in the resource to be controlled; and changing the overload threshold values into predetermined values according to a control signal from the base station manager.

2. The method as recited in claim 1 , wherein the overload grade includes a normal grade, a minor grade, a major grade and a critical grade.

3. The method as recited in claim 1 , wherein, at step f), an overload grade of a previous period and information about the overload of the current overload grade are transmitted to the base station manager along with the occurrence of the overload.