Method and apparatus for controlling transmission power of a radio transmitter

A base station serving a radio cell of a cellular radio system comprising:

• means for communicating with mobile radio stations by using radio frequency signals;
• measurement means for measuring a first reference value for the quality of radio signals received from a said mobile radio station and means for determining a second reference value for traffic load in said radio cell;
• control means for commanding said mobile radio station to increase or to decrease transmission power used by said mobile radio station for transmitting radio signals, by transmitting a message to said mobile radio station;
• wherein said control means are adapted to:
• calculate a first comparison value based on the relationship between said first reference value and a target value for said first reference value;
• calculate a second comparison value based on the relationship between said second reference value and a target value for said second reference value;
• combine said first and second comparison values to obtain a weighted comparison value which depends more on said first comparison value than on said second comparison value;
• compare said weighted comparison value with a predetermined reference value;
• and
• command said mobile radio station to increase or to decrease transmission power in response to a result of said comparison.

A mobile station of a cellular radio system comprising:

• means for communicating with a base station serving a radio cell, by using radio frequency signals;
• measurement means for measuring a first reference value for the quality of radio signals received from said base station and means for determining a second reference value for traffic load in said radio cell;
• and
• control means which are adapted to:
• calculate a first comparison value based on the relationship between said first reference value and a target value for said first reference value;
• calculate a second comparison value based on the relationship between said second reference value and a target value for said second reference value;
• combine said first and second comparison values to obtain a weighted comparison value which depends more on said first comparison value than on said second comparison value;
• compare said weighted comparison value with a predetermined reference value;
• and
• command said base station to increase or to decrease transmission power as a response to a result of said comparison, by transmitting a message to said base station.