Quality measurement of circuit-switched service in cellular radio network

A cellular radio network comprising a transmitter and a receiver, which communicates with the transmitter over a traffic channel on which a circuit-switched service is transmitted and which consists of data frames and associated control channel frames;

• the transmitter comprising means for transmitting user data to the receiver using data frames of the traffic channel;
• the transmitter comprising means for not transmitting all data frames of the traffic channel to the receiver when the user data are missing;
• the transmitter comprising means for transmitting control data to the receiver using associated control channel frames of the traffic channel;
• the transmitter comprises means for calculating the number of all frames transmitted to the receiver on the traffic channel during a certain period;
• the receiver comprises means for calculating the number of all frames received on the traffic channel and decoded correctly during a certain period;
• and
• the cellular radio network comprises means for calculating a quality value for a service to be transmitted on the traffic channel during a certain period by subtracting the number of frames transmitted during said period from the number of frames received during said period, and by dividing the difference obtained by the number of frames transmitted during said period.